Prenatal Testing Articles- American Pregnancy Association Promoting Pregnancy Wellness Tue, 14 Jun 2022 20:11:16 +0000 en-US hourly 1 https://americanpregnancy.org/wp-content/uploads/2019/03/apa-favicon-heart-2019-50x50.png Prenatal Testing Articles- American Pregnancy Association 32 32 Prenatal Tests https://americanpregnancy.org/prenatal-testing/prenatal-tests/ Thu, 30 Sep 2021 16:16:33 +0000 https://americanpregnancy.org/?p=75098 Prenatal tests are important because they give your doctor a good idea of how healthy you are and what type of problems you are most likely to experience during your pregnancy. These tests help detect any problems that could result in birth defects or genetic diseases. The test results can help you make the best […]

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Prenatal tests are important because they give your doctor a good idea of how healthy you are and what type of problems you are most likely to experience during your pregnancy. These tests help detect any problems that could result in birth defects or genetic diseases. The test results can help you make the best health care decisions before and after your child is born.

Doctors recommend some prenatal tests for all pregnant women. Only some women will need other screening tests to check for certain genetic problems.

Routine Prenatal Tests

Throughout your pregnancy, you’ll get routine exams to make sure you’re healthy. Your health care provider will check samples of your blood and urine for certain conditions, including:

She’ll also check your blood type and whether your blood cells have a protein called the Rh factor. You may also get:

  • Pap smear
  • Group B Strep screening. Your doctor will swab the skin in and around your vagina to check for this type of bacteria. This usually happens in the last month before you give birth.
  • Ultrasound. If your pregnancy is normal, you’ll have it twice, once near the beginning to see how far along you are, and the second time around 18-20 weeks to check your baby’s growth and make sure his organs are developing properly. But if you have a high-risk pregnancy, you may have additional ultrasounds.

Genetic Tests

Doctors also use prenatal tests to look for signs that your baby is at risk for certain genetic disorders or birth defects. You don’t have to have these tests, but your doctor may suggest some to make sure your baby is healthy. They’re especially important for women who have a higher risk of having a baby with a birth defect or a genetic problem. This is you if you:

  • Are over age 35
  • Have had a premature baby or a baby with a birth defect before
  • Have a genetic disorder or one that runs in your family or the other parent’s family
  • Have a medical condition like diabetes, high blood pressure, a seizure disorder, or an autoimmune disorder such as lupus
  • Have had miscarriages or stillborn babies in the past
  • Have had gestational diabetes or preeclampsia when you were previously pregnant

Some prenatal genetic tests are screening tests. They tell you if your baby has a higher risk of having a certain disorder or disease, but they can’t tell you for certain that he’ll be born with it. Other “diagnostic” tests will give you a more definite answer. Usually, you’ll get this kind after you have a positive result on a screening test.

First Trimester Screening is an early test used to detect Down syndrome or trisomy 18. The test uses an ultrasound measurement of the skin fold on the baby’s neck (nuchal translucency) and combines this with the results of  your blood test. Because this test is done between 11 and 13 weeks of pregnancy, it is called First Trimester Screening. This screening is only used to estimate the risk of Down syndrome and trisomy 18. It cannot diagnose or rule out any specific condition.

The Integrated Screening Test is a way to estimate the chance that a baby will be born with Down syndrome, trisomy 18, or an open neural tube defect. The test uses measurements from two blood tests and from your first trimester ultrasound. All of this information is combined, or integrated, with other details about you to tell you more about your developing baby.

Sequential Screen. This is similar to integrated screening, but your doctor reviews the results with you right after the first phase at 11-14 weeks. It’s not as accurate as the longer test, but it lets you know your baby’s risk earlier. If the screening finds there may be a problem, your doctor will use more tests to find out for sure. If it doesn’t find a risk, you’ll most likely get the second blood test at 16-18 weeks to be safe.

Maternal Serum Screening also know as a triple or quadruple marker test checks your blood for hormones and proteins that come from your baby or your placenta, the organ that brings him oxygen and nutrients. The test can look for three different substances (triple screening) or four (quadruple screening). Certain amounts of these mean your baby has a higher chance of having a birth defect or a genetic disease. This test happens in the second trimester, usually at 15 to 20 weeks.

Chorionic villus sampling (CVS) is a diagnostic test for identifying chromosome abnormalities and other inherited disorders. This test may be recommended by your health care provider if you or your partner has family medical histories that reveal potential risks. It’s performed between 10 and 14 weeks of pregnancy.

Amniocentesis. Amniocentesis may be recommended by your health care provider following an abnormal triple test result. Using a thin needle in your belly, your doctor will take a sample of the fluid that surrounds your baby and check it for genetic disorders or birth defects. The procedure takes about 45 minutes and does carry some risk. About 1 in 300 to 500 women will miscarry because of amniocentesis. Your doctor can tell you if it’s important for you to have this.

Compiled from these Sources:

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Integrated Screening Test https://americanpregnancy.org/prenatal-testing/integrated-screening-test/ Tue, 29 Sep 2020 17:09:36 +0000 https://americanpregnancy.org/?p=75103 The Integrated Screening Test is a way to estimate the chance that a baby will be born with Down syndrome, trisomy 18, or an open neural tube defect. The test uses measurements from two blood tests and from a first trimester ultrasound. All of this information is combined, or integrated, with other details about you […]

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The Integrated Screening Test is a way to estimate the chance that a baby will be born with Down syndrome, trisomy 18, or an open neural tube defect.

The test uses measurements from two blood tests and from a first trimester ultrasound. All of this information is combined, or integrated, with other details about you to tell you more about your developing baby.

  • The two blood tests measure proteins that are made by the developing baby and placenta. The first blood test is taken between the 11th and 13th week of your pregnancy, and the second is taken ideally between 15 and 18 weeks, although this can be measured up to the 21st week.
  • An ultrasound is taken between the 11th and 13th week, to measure the baby’s length to confirm that you are in the right timeframe for the screening, and measure the fluid-filled space at the back of the baby’s neck, which is called the nuchal translucency.

If your test result is positive (abnormal)

Your doctor will likely refer you to a genetic counselor because you are considered to be at a high risk for having a baby with Down syndrome, trisomy 18, or an open neural tube defect. On average, one in about 30 women will have a positive Integrated Screening result. A positive result does not mean that your baby has one of these problems. Other factors may affect the test results. Your provider may suggest further testing such as a detailed ultrasound of the baby’s anatomy and/or an amniocentesis.

If your result is negative (normal)

If your Integrated Screening is negative, then you are considered to be at low risk to have a baby with Down syndrome, trisomy 18, or an open neural tube defect. Screening tests can not diagnose or rule out any specific condition, nor ensure the birth of a healthy baby.

About these conditions

Integrated Screening will help find 9 out of 10 babies with Down syndrome, 8 out of 10 babies with trisomy 18, and 8 out of 10 babies with open spina bifida.

  • Down syndrome, also called trisomy 21, is a condition that causes mental retardation, heart defects, and other problems. Down syndrome is caused by an extra chromosome in the developing baby. Although the chances of having a baby with Down syndrome increase with the age of the mother, it can happen at any age. About one in 600 babies are born with Down syndrome.
  • Trisomy 18 is caused by an extra chromosome in the developing baby. Few babies with trisomy 18 survive to birth. Trisomy 18 causes mental retardation, heart defects, very poor growth, and other problems. Just like with Down syndrome, the chances of having a baby with trisomy 18 increases with the age of the mother. One baby in 6000 is born with trisomy 18.
  • A baby with an open neural tube defect (NTD) has an opening of the spine or of the head. The most common form of open NTD is called spina bifida, which happens when the spine does not close properly, exposing the spinal cord, which may become damaged. One baby out of every 1000 is born with an open NTD.

Want to Know More?

 

Sources include:

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First-Trimester Screening https://americanpregnancy.org/prenatal-testing/first-trimester-screening/ Sat, 26 Sep 2020 05:52:09 +0000 https://americanpregnancy.org/?p=730 The First-Trimester Screening is an early optional non-invasive evaluation that combines a maternal blood screening test with an ultrasound evaluation of the fetus to identify risks for specific chromosomal abnormalities, including Down Syndrome Trisomy-21 and Trisomy-18. In addition to screening for these abnormalities, a portion of the test (known as the nuchal translucency) can assist in […]

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The First-Trimester Screening is an early optional non-invasive evaluation that combines a maternal blood screening test with an ultrasound evaluation of the fetus to identify risks for specific chromosomal abnormalities, including Down Syndrome Trisomy-21 and Trisomy-18.

In addition to screening for these abnormalities, a portion of the test (known as the nuchal translucency) can assist in identifying other significant fetal abnormalities, such as cardiac disorders.  The screening test does not detect neural tube defects.

What is a first trimester screening test?

It is very important to remember what a screening test is before getting one performed. This will help alleviate some of the anxiety that can accompany test results. Screening tests do not look only at results from the blood test.  They compare a number of different factors (including age, ethnicity, results from blood tests, etc…) and then estimate what a person’s chances are of having an abnormality.

These tests DO NOT diagnose a problem; they only signal further testing should be done.

How is the first-trimester screen performed?

The blood screen involves drawing blood from the mother, which takes about 5 to 10 minutes. The blood sample is then sent to the laboratory for testing. The ultrasound is performed by an ultrasound specialist or perinatologist and takes between 20 and 40 minutes. The results are evaluated within a week of the testing.

What are the risks and side effects to the mother or baby?

Except for the discomfort of drawing blood, there are no known risks or side effects associated with the First Trimester screen. There is a 5% false-positive rate for the test. Parents should be aware of the possibility of receiving abnormal results and then finding, after further testing, the baby is normal.

Why you might consider this test

One advantage to having First Trimester Screening is that you will have information about your risk for Down syndrome and trisomy 18 earlier in the pregnancy than you would with the standard Maternal Serum Screening. While both First Trimester and Maternal Serum Screening can test for Down syndrome and trisomy 18, Maternal Serum Screening can also test for neural tube defects.

When is the first-trimester screen performed?

The First Trimester Screen is performed between the 11th and 13th week of pregnancy. Because the test is performed so early, it is often used to determine whether a mother should consider undergoing an early (first-trimester) diagnostic test, such as chorionic villus sampling, or second-trimester amniocentesis.

What does the first-trimester screen look for?

In babies who are at an increased risk for chromosomal abnormalities, increased fluid is often found in the nuchal translucency. Abnormally high or low hCG and PAPP-A levels are also often found. The first-trimester screen combines the results from these three measurements (nuchal translucency, hCG, and PAPP-A) with maternal age risk factors and determines an overall risk factor for chromosomal abnormalities.

What do the results mean?

It is important to remember the first-trimester screen is a screening test and not a diagnostic test. This test only notes a mother is at risk of carrying a baby with a genetic disorder. Many women who experience an abnormal test discover later the test proved false.

You will not be given specific quantitative values for the separate parts of the First Trimester screen. Instead, you will be told whether your results are “normal or abnormal”, and you will be given a risk level by your genetic counselor. The counselor will give you your risk factor for chromosomal abnormalities based on the test results (for example 1/250, 1/1300).

Abnormal test results warrant additional testing for making a diagnosis.  Your genetic counselor will discuss the results with you and assist you in deciding about diagnostic tests, such as CVS or amniocentesis. These invasive procedures should be discussed thoroughly with your healthcare provider and between you and your partner. Additional counseling may prove helpful.

What are the reasons for further testing?

First Trimester Screening will help find about 84 percent, or 5 out of every 6, babies with Down syndrome, and about 80 percent, or 4 out of every 5, babies with trisomy 18.

  • Down syndrome, also called trisomy 21, is caused by an extra chromosome in the developing baby. It causes mental retardation and serious heart problems. One baby out of every 600 is born with Down syndrome. Although having a baby with Down syndrome occurs more often to women who are older, it can happen at any age.
  • Trisomy 18 is caused by an extra chromosome in the developing baby. Few babies with trisomy 18 survive to birth. One baby in every 6,000 is born with trisomy 18. Trisomy 18 causes mental retardation, heart defects, very poor growth, and other problems.

 

Performing further testing allows you to confirm a diagnosis and then provides you with certain opportunities:

  • Pursue potential interventions that may exist (i.e. fetal surgery for spina bifida)
  • Begin planning for a child with special needs
  • Start addressing anticipated lifestyle changes
  • Identify support groups and resources
  • Make a decision about carrying the child to term

 

Some individuals or couples may elect not to pursue testing or additional testing for various reasons:

  • They are comfortable with the results no matter what the outcome
  • Because of personal, moral, or religious reasons, making a decision about carrying the child to term is not an option
  • Some parents choose not to allow any testing that poses any risk of harming the developing baby
  • It is important to discuss the risks and benefits of testing thoroughly with your healthcare provider. Your healthcare provider will help you evaluate if the benefits from the results could outweigh any risks from the procedure.

 

Want to Know More?

 


Compiled using information from the following sources:

  1. Dartmouth-Hitchcock Obstetrics
  2. New England Journal of Medicine, Volume 349, Number 15, October 2003, First-Trimester Screening for Trisomies21 and 18
  3. National Down Syndrome Society
  4. Nemours Foundation

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Cordocentesis : Percutaneous Umbilical Blood Sampling (PUBS) https://americanpregnancy.org/prenatal-testing/cordocentesis/ Wed, 26 Aug 2020 06:05:29 +0000 https://americanpregnancy.org/?p=736 Cordocentesis, also sometimes called Percutaneous Umbilical Cord Blood Sampling (PUBS), is a diagnostic test which examines blood from the fetus to detect fetal abnormalities. Use of cordocentesis is becoming rare because diagnostic procedures such as amniocentesis and chorionic villus sampling, which pose a lower risk of fetal death, can be used instead for prenatal diagnosis […]

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Cordocentesis, also sometimes called Percutaneous Umbilical Cord Blood Sampling (PUBS), is a diagnostic test which examines blood from the fetus to detect fetal abnormalities. Use of cordocentesis is becoming rare because diagnostic procedures such as amniocentesis and chorionic villus sampling, which pose a lower risk of fetal death, can be used instead for prenatal diagnosis of disease.

How is cordocentesis performed?

About 30 to 60 minutes before the procedure, you might be given antibiotics to reduce the risk of a uterine infection. This is usually done through a tube inserted into a vein.

Your health care provider will use ultrasound to determine the umbilical cord’s location in your uterus. You’ll lie on your back on an exam table, and your health care provider will apply a special gel to your belly. He or she will then use a small device known as an ultrasound transducer to show your baby’s position on a monitor.

Next, your health care provider will clean your belly. Sometimes medication is given to prevent discomfort during the procedure, but often it isn’t needed.

Guided by ultrasound, your health care provider will insert a thin, hollow needle through your abdominal wall and into your uterus. A small amount of blood from the vein in the umbilical cord will be withdrawn into a syringe, and the needle will be removed.

You’ll need to lie still while the needle is inserted and the blood is withdrawn. You might notice a stinging sensation when the needle enters your skin, and you might feel cramping when the needle enters your uterus.

After the procedure

After the blood sample is taken, you might have cramping or a small amount of discomfort.

Your health care provider will use an ultrasound or an external labor monitor to track your baby’s heart rate after the procedure.

When you go home, your health care provider might suggest resting for the remainder of the day. You’ll likely be able to resume normal activities the next day. Call your health care provider if you experience vaginal bleeding or fluid leakage.

The blood sample will be analyzed in a lab. Test results are typically available within days.

When is cordocentesis performed?

Cordocentesis is usually done when diagnostic information cannot be obtained through amniocentesis, CVS, or ultrasound, or if the results of these tests were inconclusive. Cordocentesis is performed after 17 weeks of pregnancy.

What does the test look for?

Cordocentesis detects chromosome abnormalities (i.e. Down syndrome) and blood disorders (i.e. fetal hemolytic disease.).

Cordocentesis may be performed to help diagnose any of the following concerns:

  • Malformations of the fetus
  • Fetal infection (i.e. toxoplasmosis or rubella)
  • Fetal platelet count in the mother
  • Fetal anemia
  • Isoimmunisation

This test is different from amniocentesis in that it does not allow testing for neural tube defects.

What do cordocentesis results mean?

Cordocentesis is a diagnostic test that detects chromosome abnormalities and certain blood disorders with high levels of accuracy. Although the probabilities of identification are high, this test does not measure the severity of these disorders. This test also does not help identify neural tube defects.

What are the risks and side effects to the mother or baby?

Although cordocentesis is considered a safe procedure, it is recognized as an invasive diagnostic test that carries a higher risk of complications to the baby, including death, than other procedures do. Your health care provider will offer the procedure only if other options aren’t available or they won’t produce results quickly enough. Miscarriage is the primary risk related to cordocentesis, occurring -1-2 times out of every 100 procedures.

Other potential side effects include:

  • Blood loss from the puncture site
  • Infection
  • Drop in fetal heart rate
  • Premature rupture of membranes
  • Infection

Contact your healthcare provider if these symptoms remain or get worse.
You should also contact your healthcare provider if you experience:

  • Fever
  • Chills
  • Leaking of amniotic fluid

What are the reasons to test or not test?

The reasons to test or not vary from person to person, couple to couple, and physician to physician.
Performing the tests and confirming the diagnosis provides you with certain opportunities:

  • Pursue potential medical interventions that may exist
  • Begin planning for a child with special needs
  • Start addressing anticipated lifestyle changes
  • Identify support groups and resources

Some individuals or couples may elect not to pursue testing or additional testing for various reasons:

  • They are comfortable with the results no matter what the outcome is
  • Because of personal, moral, or religious reasons, making a decision about carrying the child to term is not an option
  • Some parents choose not to allow any testing that poses any risk of harming the developing baby

It is important to discuss the risks and benefits of testing thoroughly with your healthcare provider. Your healthcare provider will help you evaluate if the benefits from the results could outweigh any risks from the procedure.

Want to Know More?


Compiled using information from the following sources:

1. Danforths Obtsetrics and Gynecology Ninth Ed. Scott, James R,et al, Ch.6

2. William’s Obstetrics Twenty-Second Ed. Cunningham, F. Gary, et al, Ch. 13.

3. Mayo Clinic

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Quad Screen Test https://americanpregnancy.org/prenatal-testing/quad-screen/ Sun, 26 Apr 2020 06:15:21 +0000 https://americanpregnancy.org/?p=742 The quad screen test is a maternal blood screening test that looks for four specific substances: AFP, hCG, Estriol, and Inhibin-A. AFP: alpha-fetoprotein is a protein that is produced by the fetus hCG: human chorionic gonadotropin is a hormone produced within the placenta Estriol: estriol is an estrogen produced by both the fetus and the […]

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The quad screen test is a maternal blood screening test that looks for four specific substances: AFP, hCG, Estriol, and Inhibin-A.
AFP: alpha-fetoprotein is a protein that is produced by the fetus
hCG: human chorionic gonadotropin is a hormone produced within the placenta
Estriol: estriol is an estrogen produced by both the fetus and the placenta
Inhibin-A: inhibin-A is a protein produced by the placenta and ovaries

What is a Quad Screening Test?

The quad screen is a maternal blood screening test which is similar to the Triple Screen Test (also know as AFP Plus and the Multiple Marker Screening). However, the quad screen looks for not only the three specific substances evaluated in those tests (AFP, hCG, and Estriol) but also a fourth substance known as Inhibin-A.
The screen is essentially the same as the screening tests that look for only three substances, except the likelihood of identifying pregnancies at risk for Down Syndrome is higher through the evaluation of Inhibin-A levels. The false-positive rate of the test is also lower.
It is very important to remember what a screening test is before getting one performed. This will help alleviate some of the anxiety that can accompany test results. Screening tests do not look only at results from the blood test. They compare a number of different factors (including age, ethnicity, results from blood tests, etc…) and then estimate what a person’s chances are of having an abnormality.
These tests DO NOT diagnose a problem; they only signal that further testing should be done.

How is the quad screen test performed?

The quad screen test involves drawing blood from the mother, which takes about 5 to 10 minutes. The blood sample is then sent to the laboratory for testing. The results usually take a few days to receive.

What are the risks and side effects to the mother or baby?

Except for the discomfort of drawing blood, there are no known risks or side effects associated with the quad screen test.

When is the quad screen test performed?

The quad screen test is performed between the 16th and 18th week of pregnancy.
All pregnant women should be offered the quad screen, but it is recommended for women who:

What does the quad screen test look for?

The quad screen measures high and low levels of AFP, abnormal levels of hCG and estriol, and high levels of Inhibin-A. The results are combined with the mother’s age and ethnicity in order to assess the probabilities of potential genetic disorders. High levels of AFP may suggest that the developing baby has a neural tube defect such as spina bifida or anencephaly.

However, the most common reason for elevated AFP levels is inaccurate dating of the pregnancy.

Low levels of AFP and abnormal levels of hCG and estriol may indicate that the developing baby has Trisomy 21(Down syndrome), Trisomy 18 (Edwards Syndrome) or another type of chromosome abnormality.

What do the quad screen results mean?

It is important to remember that the quad screen is a screening test and not a diagnostic test. This test only notes that a mother is at risk of carrying a baby with a genetic disorder. Many women who experience an abnormal test result go on to deliver healthy babies. Abnormal test results warrant additional testing in order to make a diagnosis.

A more conservative approach involves performing a second quad-screen followed by a high definition ultrasound. If the testing still maintains abnormal results, a more invasive procedure such as amniocentesis may be performed.

Any invasive procedure should be discussed thoroughly with your healthcare provider and between you and your partner. Additional counseling and discussions with a counselor, social worker or minister may prove helpful.

What are the reasons for further testing?

The quad screen is a routine screening that poses no known risks to the mother or baby. The quad screen results may warrant additional testing. The reasons to pursue further testing or not vary from person to person and couple to couple.

Performing further testing allows you to confirm a diagnosis and then provides you with certain opportunities:

  • Pursue potential interventions that may exist (i.e. fetal surgery for spina bifida)
  • Begin planning for a child with special needs
  • Start addressing anticipated lifestyle changes
  • Identify support groups and resources
  • Make a decision about carrying the child to term

Some individuals or couples may elect not to pursue testing or additional testing for various reasons:

  • They are comfortable with the results no matter what the outcome is
  • Because of personal, moral, or religious reasons, making a decision about carrying the child to term is not an option
  • Some parents choose not to allow any testing that poses any risk of harming the developing baby

It is important to discuss the risks and benefits of testing thoroughly with your healthcare provider. Your healthcare provider will help you evaluate if the benefits from the results could outweigh any risks from the procedure.

Want to Know More?

 

Compiled using information from the following sources:

1. WebMD

https://www.webmd.com

2. March of Dimes

www.marchofdimes.com

3. Second-trimester maternal serum screening for fetal open neural tube defects and aneuploidy”, American College of Medical Genetics Policy Statement (2004).

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Alpha-Fetoprotein Test (AFP) https://americanpregnancy.org/prenatal-testing/alpha-fetoprotein-test/ Sun, 26 Apr 2020 06:11:44 +0000 https://americanpregnancy.org/?p=738 The Alpha-Fetoprotein Test (AFT) test is a screening test that examines the level of alpha-fetoprotein in the mother’s blood during pregnancy. This is not a diagnostic test.  It is often part of the triple screen test that assesses whether further diagnostic testing may be needed. What is a screening test and how is it done? Screening […]

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The Alpha-Fetoprotein Test (AFT) test is a screening test that examines the level of alpha-fetoprotein in the mother’s blood during pregnancy. This is not a diagnostic test.  It is often part of the triple screen test that assesses whether further diagnostic testing may be needed.

What is a screening test and how is it done?

Screening tests, like the Alpha-Fetoprotein Test do not look only at results from the blood test.  They compare a number of different factors (including age, ethnicity, results from blood tests, etc…) and then estimate what a person’s chances are of having an abnormality. These tests DO NOT diagnose a problem; they only signal that further testing should be done.

To perform the AFP test, blood is drawn from veins in the mother’s arm and sent off to a laboratory for analysis. Results are usually returned between one and two weeks.

When is the Alpha-Fetoprotein Test Test performed?

The AFP test may be performed between the 14th and 22nd weeks of pregnancy, however, it seems to be most accurate during the 16th to 18th week.  Your levels of AFP vary during pregnancy so accurate pregnancy dating is imperative for more reliable screening results.

All pregnant women should be offered the AFP screening, but it is especially recommended for:

What does the AFP test look for?

Alpha-fetoprotein (AFP) is found in both fetal serum and also amniotic fluid. This protein is produced early in gestation by the fetal yolk sac and then later in the liver and gastrointestinal tract. The true function of AFP is unknown. We do know that this protein’s level increases and decreases during certain weeks of pregnancy which is why accurate pregnancy dating is crucial.

The AFP test is measuring high and low levels of alpha-fetoprotein.  The results are combined with the mother’s age and ethnicity in order to assess the probabilities of potential genetic disorders.

High levels of AFP may suggest the developing baby has a neural tube defect such as spina bifida or anencephaly.
High levels of AFP may also suggest defects with the esophagus or failure of your baby’s abdomen to close. However, the most common reason for elevated AFP levels is inaccurate dating of the pregnancy.

Low levels of AFP and abnormal levels of hCG and estriol may indicate the developing baby has Trisomy 21( Down syndrome), Trisomy 18 (Edwards Syndrome) or another type of chromosome abnormality.

Abnormal levels may also be a result of the following:

What do Alpha-Fetoprotein Test results mean?

It is important to remember that the AFP is a screening test and not a diagnostic test. This test only notes that a mother is at risk of carrying a baby with a potential disorder.

There are approximately 25 to 50 abnormal test AFP results for every 1,000 pregnancies tested.
Of these abnormal results, only 1 in 16 to 1 in 33 will actually have a baby that has been affected by a neural tube defect or other condition.

75% to 90% of babies with neural tube #defects are discovered through AFP screening.

Abnormal test results warrant additional testing for making a diagnosis.

A more conservative approach involves performing a second MSAFP or complete triple screen test followed by a high definition ultrasound.

If the testing still maintains abnormal results, a more invasive procedure such as amniocentesis may be performed.
Invasive procedures should be discussed thoroughly with your healthcare provider. It is also important to talk through further testing with your partner. Additional counseling and discussions with a counselor, social worker or minister may prove helpful.

What are the risks and side effects of AFP to the mother or baby?

Except for the discomfort of drawing blood, there are no risks or side effects associated with the AFP.

What about further testing?

The Alpha-fetoprotein test is not an invasive procedure and poses no known risks to the mother or baby. The AFP results may warrant additional testing.

The reasons to pursue further testing or not may vary from person to person and couple to couple. Performing further testing allows you to confirm a diagnosis and then provides you with certain opportunities:

  • Pursue potential medical interventions that may exist
  • Begin planning for a child with special needs
  • Start addressing anticipated lifestyle changes
  • Identify support groups and resources
  • Make a decision about carrying the child to term

Some individuals or couples may elect not to pursue further testing for various reasons:

  • They are comfortable with the results no matter what the outcome is
  • Because of personal, moral, or religious reasons, making a decision about carrying the child to term is not an option
  • Some parents choose not to allow any testing that poses any risk of harming the developing baby

It is important to discuss the risks and benefits of further testing thoroughly with your healthcare provider. Your healthcare provider will help you evaluate if the benefits from the results could outweigh any risks from the procedure.

Want to Know More?

Compiled using information from the following sources:

1. William’s Obstetrics Twenty-Second Ed. Cunningham, F. Gary, et al, Ch. 13.

2. Mayo Clinic Complete Book of Pregnancy & Baby’s First Year Johnson, Robert V., et al, Ch. 6.

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Chorionic Villus Sampling: CVS https://americanpregnancy.org/prenatal-testing/chorionic-villus-sampling/ Sun, 26 Apr 2020 05:45:06 +0000 https://americanpregnancy.org/?p=727 Chorionic villus sampling often referred to as CVS, is a diagnostic test for identifying chromosome abnormalities and other inherited disorders. This test may be recommended by your health care provider if you or your partner has family medical histories that reveal potential risks. The main advantage of CVS is you receive results early in your […]

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Chorionic villus sampling often referred to as CVS, is a diagnostic test for identifying chromosome abnormalities and other inherited disorders. This test may be recommended by your health care provider if you or your partner has family medical histories that reveal potential risks. The main advantage of CVS is you receive results early in your pregnancy.

How is the chorionic villus sampling (CVS) performed?

CVS is a diagnostic procedure which involves removing some chorionic villi cells from the placenta at the point where it attaches to the uterine wall.

There are two ways samples are collected:

Transcervical: An ultrasound guides a thin catheter through the cervix to your placenta. The chorionic villi cells are gently suctioned into the catheter. This is the most common method.

Transabdominal: An ultrasound guides a long thin needle through the abdomen to your placenta. The needle draws a sample of tissue and then is removed. This procedure is similar to that of amniocentesis.

Before the test, the doctor uses ultrasound to figure out which way to do the CVS. The simplest route to the placenta is usually the safest for the mother and baby. Usually the doctor will need only one try to obtain the sample, except in the case of twins where one procedure may be needed for each baby. In some cases, a second attempt will be needed for a single baby to obtain enough placental cells. Rarely, it is not possible to obtain enough placental cells to do the testing or it is not possible to reach the placenta to obtain a sample.

The CVS procedure collects larger samples and provides faster results than amniocentesis. Results may be received between one to seven days.

When is chorionic villus sampling (CVS) performed?

CVS is usually performed between 10 and 13 weeks from your last menstrual period. CVS may be chosen over amniocentesis because it may be performed earlier in the pregnancy. If you would like to have this testing done contact your doctor early in your pregnancy to schedule the procedure.

What does the test look for?

Chorionic villus sampling looks at a baby’s chromosomes by testing the placental cells for chromosome abnormalities. The placenta and the baby have the same genetic information, so the laboratory can grow and then study the placental cells to learn about the baby. Chromosomes are small packages of DNA that contain all of our genes, which provide the instructions for human development. In most individuals, each cell contains a total of 46 chromosomes. CVS can detect if the baby has an extra or missing chromosome or large changes to chromosome structure. Changes to chromosomes may lead to serious birth defects and/or mental retardation.

  • CVS tissue can be used to test for certain inherited genetic diseases. If a couple is at known risk to have a child with a certain genetic condition such as cystic fibrosis, sickle cell disease, or Tay-Sachs disease, it is possible to test the pregnancy for this condition using CVS.
  • Down syndrome, or trisomy 21, is the most common chromosome condition detected. It is caused when there is an extra 21st chromosome in each cell, causing a total of 47 chromosomes. People with Down syndrome have mild to moderate mental retardation and may have certain birth defects.
  • Trisomy 18, or Edward syndrome, is less common than Down syndrome. It is caused when there is an extra 18th chromosome instead of the 21st for Down syndrome. Few babies with Trisomy 18 survive to birth. Trisomy 18 causes mental retardation, heart defects, very poor growth and other problems.
  • CVS does not test for birth defects including heart defects or spina bifida. Couples who desire screening for spina bifida may wish to consider having a test to measure the alpha fetoprotein chemical in the mother’s blood. You may also want to consider an ultrasound, which can detect most cases of spina bifida between 18 and 20 weeks of pregnancy.

This test is different from amniocentesis in that it does not allow for testing for neural tube defects.

Chorionic villus sampling also provides access to DNA for paternity testing prior to delivery. DNA is collected from the potential father and is compared to DNA obtained from the baby during chorionic villus sampling. The results are accurate (99%) for determining paternity.

Processing the test

  • On average, results take about 10-14 days.
  • In situations where information is needed more quickly, preliminary results of the CVS may be available in 48 hours.
  • Sometimes the results will take longer than expected if the placental cells do not grow in the laboratory as quickly as expected.
  • Very rarely, placental cells will not grow at all and the results of the CVS or any special tests that were ordered with the CVS will not be reported. In this case, a second CVS may be needed.
  • If the pregnancy is beyond 14 weeks, an amniocentesis could be an option.
  • If any special genetic testing was done with the CVS, the timing for these results will depend on the condition being tested for and may take over a month.

Accuracy of CVS

The accuracy of this test for the most common problems is approximately 99 percent. If any special genetic testing was done on the CVS sample, the accuracy will depend on the condition being tested and on the laboratory doing the testing.

What do chorionic villus sampling (CVS) results mean?

CVS is a diagnostic test that detects chromosome abnormalities and genetic disorders with high levels of accuracy (98-99%). Although the probabilities of identification are high, this test does not measure the severity of these disorders. This test does not help identify neural tube defects.

Are there risks or side effects to the mother or baby?

Although CVS is considered to be a safe procedure, it is recognized as an invasive diagnostic test that does pose potential risks. Miscarriage is the primary risk related to CVS occurring 1 out of every 100 procedures.

CVS is not recommended for women who:

Transcervical CVS is not recommended for women who:

Since CVS involves entering the uterus with either a needle or a catheter, women having CVS may experience discomfort, usually described as pressure or cramping. Some cramping for several hours after the procedure is common. If the procedure is done using a needle, soreness, tenderness, or bruising at the site of the needle entry may occur. If the procedure is done using a catheter, light vaginal blood spotting may occur.

Contact your healthcare provider if these symptoms remain or get worse.

You should also contact your healthcare provider if you experience:

  • Fever
  • Chills
  • Leaking of amniotic fluid

According to the Mayo Clinic, there is a 1% chance of getting false positive results. A false positive occurs when the test indicates that the fetus has an abnormality, but it actually does not.

What are the reasons to test or not test?

The reasons to test or not test vary from person to person and couple to couple.
Performing the tests and confirming the diagnosis provides you with certain opportunities:

  • Pursue potential interventions that may exist
  • Begin planning for a child with special needs
  • Start addressing anticipated lifestyle changes
  • Identify support groups and resources
  • Make a decision about carrying the child to term

Some individuals or couples may elect not to pursue testing or additional testing for various reasons:

  • They are comfortable with the results no matter what the outcome is
  • Because of personal, moral, or religious reasons, making a decision about carrying the child to term is not an option
  • Some parents choose not to allow any testing that poses any risk of harming the developing baby

It is important to discuss the risks and benefits of testing thoroughly with your healthcare provider. Your healthcare provider will help you evaluate if the benefits from the results could outweigh any risks from the procedure.

Want to Know More?


Compiled using information from the following sources:

1. Mayo Clinic Complete Book of Pregnancy & Baby’s First Year. Johnson, Robert V., M.D., et al, Ch. 11.

2. Williams Obstetrics Twenty-Second Ed. Cunningham, F. Gary, et al, Ch. 13.

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Ultrasound: Sonogram https://americanpregnancy.org/healthy-pregnancy/pregnancy-health-wellness/ultrasound/ Sun, 26 Apr 2020 05:38:39 +0000 https://americanpregnancy.org/?p=720 What is an Ultrasound Exam? This procedure uses high-frequency sound waves to scan a woman’s abdomen and pelvic cavity, creating a picture (sonogram) of the baby and placenta. Although the terms ultrasound and sonogram are technically different, they are used interchangeably and refer to the same exam. There are basically seven different exams, but the […]

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What is an Ultrasound Exam?

This procedure uses high-frequency sound waves to scan a woman’s abdomen and pelvic cavity, creating a picture (sonogram) of the baby and placenta. Although the terms ultrasound and sonogram are technically different, they are used interchangeably and refer to the same exam.

There are basically seven different exams, but the basic process is the same:

Transvaginal Scans – Specially designed probe transducers are used inside the vagina to generate sonogram images. Most often used during the early stages of pregnancy.

Standard Ultrasound – Traditional exam which uses a transducer over the abdomen to generate 2-D images of the developing fetus.

Advanced Ultrasound – This exam is similar to the standard ultrasound, but the exam targets a suspected problem and uses more sophisticated equipment.

Doppler Ultrasound – This imaging procedure measures slight changes in the frequency of the ultrasound waves as they bounce off moving objects, such as blood cells.

3-D Ultrasound – Uses specially designed probes and software to generate 3-D images of the developing fetus.

4-D or Dynamic 3-D Ultrasound – Uses specially designed scanners to look at the face and movements of the baby prior to delivery.

Fetal Echocardiography – Uses ultrasound waves to assess the baby’s heart anatomy and function. This is used to help assess suspected congenital heart defects.

How is the test performed?

  • You do not need to fast or have a full bladder before your ultrasound.
  • An ultrasound generally takes from 30 to 60 minutes, depending on how detailed the scan is.
  • After you lie down on the examination table, the sonographer will apply a warm gel to your belly so that the ultrasound probe can make good contact.
  • The sonographer will move a smooth probe back and forth across your abdomen and watch the images on a monitor. You may be asked to turn on one side if images are needed from a different position. The sound waves bounce off bones and tissue returning back to the transducer to generate black and white images of the fetus. You will be able to see the scan as it takes place, and ask the sonographer questions about what you see.
  • Sometimes, your provider may determine that for certain conditions or to look at the baby from a particular angle, you may need a transvaginal ultrasound, which involves a probe placed in the vagina instead of on top of your abdomen.

When are the tests performed?

Ultrasounds may be performed at any point during pregnancy, and the results are seen immediately on a monitor during the procedure. Transvaginal scans may be used early in pregnancy to diagnose a potential ectopic or molar pregnancies.
There is not a recommended number of ultrasounds that should be performed during routine prenatal care. Because ultrasound should only be used when medically indicated, many healthy pregnancies will not require the test. The average number of test varies with each healthcare provider.

Additional ultrasounds might be ordered separately if your healthcare provider suspects a complication or problem related to your pregnancy.

What does the ultrasound look for?

This is a diagnostic procedure that detect or aid in the detection of abnormalities and conditions related to pregnancy. Ultrasounds are usually combined with other tests, such as triple tests, amniocentesis, or chorionic villus sampling, to validate a diagnosis.

An ultrasound exam may be performed throughout pregnancy for the following medically-necessary reasons:

First Trimester:

  • Confirm viable pregnancy
  • Confirm heartbeat
  • Measure the crown-rump length or gestational age
  • Confirm molar or ectopic pregnancies
  • Assess abnormal gestation

Second Trimester:

  • Diagnose fetal malformation
    • Weeks 13-14 for characteristics of potential Down syndrome
    • Weeks 18-20 for congenital malformations
  • Structural abnormalities
  • Confirm multiples pregnancy
  • Verify dates and growth
  • Confirm intrauterine death
  • Identify hydramnios or oligohydramnios – excessive or reduced levels of amniotic fluid
  • Evaluation of fetal well-being

Third Trimester:

  • Identify placental location
  • Confirm intrauterine death
  • Observe fetal presentation
  • Observe fetal movements
  • Identify uterine and pelvic abnormalities of the mother

What are the risks and side effects to the mother or baby?

The ultrasound is a noninvasive procedure which, when used properly, has not demonstrated fetal harm. The long-term effects of repeated ultrasound exposures on the fetus are not fully known. It is recommended that ultrasound only be used if medically indicated.

Answers to common questions:

If an ultrasound is done at 6 to 7 weeks and a heartbeat is not detected, does that mean there is a problem?

No, it does not mean there is a problem. The heartbeat may not be detected for reasons that include: tipped uterus, larger abdomen, or inaccurate dating with last menstrual period. Heartbeats are best detected with transvaginal ultrasounds early in pregnancy.

Concern typically develops if there is no fetal heart activity in an embryo with a crown-rump length greater than 5mm. If you receive a test after week 6, your healthcare provider will begin to be concerned, if there is no gestational sac.

How accurate are the tests in calculating gestational age?

Your healthcare provider will use hormone levels in your blood, the date of your last menstrual period and, in some cases, results from an ultrasound to generate an estimated gestational age. However, variations in each woman’s cycle and each pregnancy may hinder the accuracy of the gestational age calculation.

If your healthcare provider uses an ultrasound to get an estimated delivery date to base the timing of your prenatal care, the original estimated gestational age will not be changed.

Why do some healthcare providers schedule ultrasounds differently?

If there are any questions regarding gestational age, placenta location, or possible complications then more ultrasounds may be scheduled. Because this test should only be used when medically indicated, many healthy pregnancies will not require one. The average number varies with each healthcare provider.

What is the test’s accuracy in determining the conception date to determine paternity?

Your healthcare provider will use hormone levels in your blood, the date of your last menstrual period and, in some cases, results from an ultrasound to generate an expected date of conception. However, many differences in each woman’s cycle may hinder the accuracy of the conception date calculation.

The viability of sperm varies as well, which means intercourse three to five days prior to ovulation may result in conception. Ultrasound dating of conception is not reliable for determining paternity because the test can be off by at least 5-7 days in early pregnancy.

When can an ultrasound determine the sex of the baby?

You may have an ultrasound between 18 to 20 weeks to evaluate dates, a multiples pregnancy, placenta location or complications. It may also be possible to determine the gender of your baby during this test. Several factors, such as the stage of pregnancy and position of the fetus, will influence the accuracy of the gender prediction.
To be 100% sure you will have an anxious wait until birth!

Are ultrasounds a necessary part of prenatal care?

Ultrasounds are only necessary if there is a medical concern. As noted above, ultrasounds enable your healthcare provider to evaluate the baby’s well being as well as diagnose potential problems. For women with an uncomplicated pregnancy, an ultrasound is not a necessary part of prenatal care.

Want to Know More?


Compiled using information from the following sources:

1. William’s Obstetrics Twenty-Second Ed. Cunningham, F. Gary, et al, Ch. 16.

2. American Institute of Ultrasound in Medicine

https://www.aium.org

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Getting a Pregnancy Urinalysis: About Prenatal Urine Tests https://americanpregnancy.org/prenatal-testing/urine-test-urinalysis/ Sun, 26 May 2019 05:36:50 +0000 https://americanpregnancy.org/?p=718 A urine test is a routine test used by your healthcare provider as part of your prenatal care to measure protein, sugar. Although urine tests are used in screening for pregnancy, this article is discussing urine tests as part of your routine prenatal care. Why is a urine analysis important during pregnancy? A urine test […]

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A urine test is a routine test used by your healthcare provider as part of your prenatal care to measure protein, sugar. Although urine tests are used in screening for pregnancy, this article is discussing urine tests as part of your routine prenatal care.

Why is a urine analysis important during pregnancy?

A urine test is used to assess bladder or kidney infections, diabetes, dehydration, and Preeclampsia by screening for high levels of sugars, proteins, ketones, and bacteria. High levels of sugars may suggest Gestational Diabetes, which may develop around the 20th week of pregnancy.

Higher levels of protein may suggest a possible urinary tract infection or kidney disease. Preeclampsia may be a concern if higher levels of protein are found later in pregnancy, combined with high blood pressure.

Sugar: Sugar in your urine does not mean you are diabetic. It is normal for your kidneys to leak sugar from your bloodstream into your urine. This is particularly expected if you eat a large meal or drink a really sweet beverage.

You should be tested for gestational diabetes if:

  • Consistent levels of sugar (glucose) are detected and/or
  • You feel tired or lethargic
  • You are consistently thirsty
  • You are losing weight

If protein is found in your urine late in pregnancy this may be a sign of preeclampsia.
Your healthcare provider will examine you for preeclampsia if:

  1. Consistent levels of sugar (glucose) are detected
  2. You have high blood pressure
  3. You have swelling in your face and hands

High levels of ketones indicate you are not getting enough to eat or that you may be dehydrated.
Your healthcare provider may retrieve a second urine sample collected through a catheter before determining the type of antibiotics needed.

How is a urine test performed?

Your healthcare provider will ask you to collect a small sample of clean, midstream urine in a sterile plastic cup. Chemically prepared testing strips are dipped into your sample of urine to screen for certain indicators. A more in-depth analysis may be done by having your urine sample assessed by a laboratory.

When are urine tests performed?

A urine test should be expected during your first prenatal exam and then at least periodically in future prenatal visits.
It would be normal for your healthcare provider to monitor your urine during each visit.

What does the urine test look for?

A urine test is used to assess bladder or kidney infections, diabetes, dehydration, and Preeclampsia by screening for high levels of sugars, proteins, ketones, and bacteria. High levels of sugars may suggest Gestational Diabetes, which may develop around the 20th week of pregnancy.

Higher levels of protein may suggest a possible urinary tract infection or kidney disease. Preeclampsia may be a concern if higher levels of protein are found later in pregnancy, combined with high blood pressure.

Want to Know More?


Compiled using information from the following sources:

1. March of Dimes: www.marchofdimes.org

2. Nemours Foundation: https://www.kidshealth.org

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Glucose Tolerance Test https://americanpregnancy.org/healthy-pregnancy/pregnancy-health-wellness/glucose-tolerence-test/ Fri, 26 Apr 2019 06:34:50 +0000 https://americanpregnancy.org/?p=757 Pregnant women can develop a condition known as Gestational Diabetes (diabetes brought on by pregnancy) which can pose a risk to both mother and baby. A glucose tolerance test is a common type of testing for potential gestational diabetes. There are several tests intended to identify gestational diabetes in pregnant women. The first, called the Glucose Challenge […]

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Pregnant women can develop a condition known as Gestational Diabetes (diabetes brought on by pregnancy) which can pose a risk to both mother and baby. A glucose tolerance test is a common type of testing for potential gestational diabetes.

There are several tests intended to identify gestational diabetes in pregnant women. The first, called the Glucose Challenge Screening, is a preliminary screening test performed between 26-28 weeks. If a woman tests positive during this screening test, the second test, called the Glucose Tolerance Test, may be performed. This test will diagnose whether diabetes exists or not by indicating whether or not the body is using glucose (a type of sugar) effectively.
The Glucose Challenge Screening is now considered to be a standard test performed during the early part of the third trimester of pregnancy.

What is the Glucose Challenge Screening Test?

No preparation is required prior to the test. During the test, the mother is asked to drink a sweet liquid (glucose) and then will have blood drawn one hour from having the drink, as blood glucose levels normally peak within one hour. No fasting is required prior to this test.

The test evaluates how your body processes sugar. A high level in your blood may indicate your body is not processing sugar effectively (positive test). If the results of this screen are positive, the woman may have the Glucose Tolerance Test performed. It is important to note that not all women who test positive for the Glucose Challenge Screening test are found to have diabetes upon further diagnosis.

What is the Glucose Tolerance Test?

Prior to the taking the glucose tolerance test, your doctor will ask you to make sure and eat at least 150 mg of carbohydrates (about what you will get from a slice or two of bread) for three days prior to the time you will be asked to fast. You will not be permitted to eat or drink anything but sips of water for 14 hours prior to the test, so it is best to schedule the test for first thing in the morning.

Additionally, you should plan to have someone drive you to and from the test since your energy levels may be low and there is a slight possibility you may feel light-headed.

3-Hour Glucose Test

When you arrive, the technician will draw blood to measure your baseline “fasting blood glucose level”. You will be asked to drink a larger volume (or more concentrated solution) of the glucose drink than was used in the initial Glucose Challenge Screening test. Your blood will be drawn and tested every hour for the next three hours.

The following are the values that the American Diabetes Association considers to be abnormal during the Glucose Tolerance Test:

Interval Abnormal reading
Fasting 95 mg/dl or higher
One hour 180 mg/dl or higher
Two hours 155 mg/dl or higher
Three hours 140 mg/dl or higher

What if my Glucose Tolerance Test Results are Abnormal?

If only one of your readings comes back abnormal, your doctor may suggest some changes to your diet and/or test you again later in the pregnancy. If two or more of your readings come back abnormal, you’ll be diagnosed with Gestational Diabetes and your doctor or midwife will talk to you about a treatment plan. Treating diabetes during pregnancy is extremely important to protect the health of both mother and baby.

Want to Know More?


Compiled using information from the following sources:

1. American Diabetes Association

https://www.diabetes.org

2. Emedicine

https://www.emedicine.com

3. National Institute of Diabetes and Digestive and Kidney Diseases

https://www.niddk.nih.gov

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