Usa Blood Test for Women to Check on Baby Helathes Pregnnacy

Credit... Maggie Chiang

Everything You Need to Know About Blood Tests During Pregnancy

They can reveal valuable health information about you and your baby, but some come with more considerations than others.

Credit... Maggie Chiang

• April 17, 2020

This guide was originally published on May 13, 2019 in NYT Parenting.

For many parents-to-be, the barrage of tests and recommendations during pregnancy can lead to a mixed bag of emotions. On the one hand, they can provide relief in knowing that you and your baby are healthy. On the other, they can be overwhelming and stressful, revealing more information than you and your partner are comfortable with, compounding the anxiety of pregnancy.

Dr. Britton Rink, M.D., an ob-gyn and director of medical genetics for the Mount Carmel Health System in Columbus, Ohio, said that the heavy marketing of genetic tests by the companies that make them can be valuable in informing patients of their testing options, "but it can also be difficult for patients to get the message that all testing is optional."

To help you understand the ins and outs of prenatal blood testing, I reviewed the American College of Obstetricians and Gynecologists' guidelines, read several scientific studies and spoke with two ob-gyns and a prenatal genetic counselor.

During your first trimester, screen for the basics.

Between nine and 10 weeks of pregnancy, your doctor will likely suggest that you get a blood test that checks for the following:

Rh factor; or Rhesus factor. If your blood cells have this protein, you're Rh positive (as most people are); if they don't, you're Rh negative. If you happen to have a different Rh status than your fetus —if you're negative and your fetus is positive, for example — your body might view your baby's red blood cells as foreign and produce antibodies to attack them. An opposite Rh status probably won't be an issue if it's your first pregnancy, but the antibodies can stick around and attack a baby's red blood cells in subsequent pregnancies, potentially causing life-threatening anemia for your baby. If you have an Rh incompatibility, your doctor might prescribe a vaccine-like medication called Rh immune-globulin, which halts your body's production of these antibodies to protect your baby.

Sexually transmitted infections . It's possible to pass certain S.T.I.s — such as H.I.V., chlamydia, gonorrhea, syphilis or hepatitis B — to your baby (either during pregnancy or birth); potentially leading to a range of complications including miscarriage, preterm delivery, birth defects, blindness or newborn death. Getting tested for S.T.I.s early can help prevent you from passing them on, said Dr. Hyagriv Simhan, M.D., a professor of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh School of Medicine.

If you're younger than 25 or at high risk for some or all of these infections, your doctor will likely recommend testing. Certain states require S.T.I. testing for pregnant women as a public health measure. Check with your doctor about what is required.

[What to know about sexually transmitted infections and pregnancy ]

Anemia. When you don't have enough healthy red blood cells to carry oxygen to your tissues, anemia can result. Mild anemia is common during pregnancy, but severe anemia can increase the risk that you will have a preterm delivery or a baby with low birth weight, according to the American Society of Hematology, so it's important to test for it.

Consider the pros and cons of genetic screening tests.

Carrier screening. Before your pregnancy or during your first trimester, your doctor might recommend a type of genetic blood test called carrier screening, which scans your DNA for genetic mutations associated with certain genetic disorders that you might pass on to your child. Often, your decision to test will be based on your family history or ethnicity.

Sickle cell disease, for example, is more common in people of African descent; and conditions like Gaucher disease, Niemann-Pick disease and Tay-Sachs disease are more common in people with Eastern European or Ashkenazi Jewish heritage. You might also screen for genetic conditions you know run in your family, such as Huntington's disease. Cystic fibrosis, which damages a baby's lungs and digestive system, is one of the most common genetic disorders, and therefore testing for it is often recommended early in pregnancy.

One major drawback to carrier screening tests, according to Blair Stevens, M.S., a licensed genetic counselor specializing in prenatal and reproductive genetics at the University of Texas, is that they won't tell you with certainty whether your baby has a given genetic condition — only her risk for it. While this knowledge may be enough for some people, others may find the uncertainty stressful.

Keep in mind, too, that the number of conditions you screen for is up to you, but more is not always better. "The more conditions you include, the greater the chance that you would find a condition in which you're a carrier," cautioned Dr. Rink, which could cause unnecessary anxiety. Also remember that passing a genetic mutation on to your children is not necessarily a death sentence for them: Some may never develop that condition or may only have mild symptoms.

The number of conditions you choose to screen for will depend on your and your partner's risk, family history and desire for information. You should also consider cost, since carrier testing may or may not be covered by insurance. Talk with your doctor about what's right for you.

Genetic screening for baby. As soon as 10 weeks into your pregnancy, your doctor may ask if you're interested in blood testing that determines your baby's risk for certain chromosomal conditions. As with carrier screening, this test won't definitively say whether your baby has a condition, it just reveals their risk for it.

Genetic screening could involve a combination of blood tests that measure certain pregnancy-related proteins in your body, plus an ultrasound, which checks for birth defects by measuring the thickness of your fetus's neck (usually done between weeks 11 and 14 of pregnancy). Or, you might opt for a newer type of blood test, known as cell-free DNA screening (or non-invasive prenatal testing), which can be done starting at week 10. This test scans your baby's DNA, which is floating around your own blood, for abnormalities — such as too many or not enough chromosomes.

Doctors commonly screen for Down syndrome (trisomy 21), Edwards syndrome (trisomy 18) and Patau syndrome (trisomy 13) during this test. All three are associated with intellectual disabilities and birth defects, though Down syndrome is the most well-known and common condition, occurring in about 1 in every 700 babies born in the United States.

Chromosomal abnormalities can happen by chance, "so anyone that's pregnant can have a baby with a chromosome condition, regardless if their family is healthy or if they're healthy," said Stevens.

Some parents-to-be also get this test to determine their fetus's sex, though keep in mind that it might reveal abnormalities in the sex chromosomes, said Dr. Rink, which you may not be anticipating. These can include Turner syndrome in females, where one X chromosome is missing or altered; or Klinefelter syndrome in males, where they're born with an extra X chromosome.

Doctors generally recommend genetic screening for pregnant women 35 or older, said Dr. Simhan, since the risk for chromosomal abnormalities (a risk all pregnancies carry) increases around that age. You can opt to do it during your second trimester, though that may breed less accurate results, according to Dr. Simhan, so having it done in your first trimester is preferred.

Consider the pros and cons of diagnostic testing.

Diagnostic testing, on the other hand, can tell you with much more certainty than a screening test whether your baby has certain genetic conditions. This test is done on cells taken from the fetus or placenta, and is usually offered after a screening test suggests that your baby might be at high risk for a genetic condition. However, some patients may skip the screening step completely and jump right to diagnostic testing if they prefer more definitive information.

The major downside to diagnostic testing, however, is that it's invasive. The two diagnostic procedures available involve inserting a thin needle into your belly to remove a small sample of amniotic fluid or tissue from the placenta. Both procedures carry a slight risk of miscarriage: 1 percent or less. You might feel that this risk isn't worth the answers the test provides. But if you and your partner are both found to be carriers of a certain genetic condition during the carrier screening test, you may want to think about diagnostic testing.

Even diagnostic tests have limits, though, according to Stevens: "There's simply no genetic test that can rule out every genetic condition or birth defect."

During your second trimester, consider the quad and gestational diabetes screens.

Quad screen. This blood test, also called a maternal serum screen, checks for Down syndrome, trisomy 18 and neural tube defects (birth defects that affect the brain, spine or spinal cord). The most common neural tube defect is spina bifida, in which the spinal cord doesn't develop properly. A quad screen is typically recommended if you didn't have genetic screening done in your first trimester. It can also be combined with first trimester screening to get a more accurate picture of Down syndrome risk, though as with the first trimester screens, it can't definitively say whether your baby has a given condition.

Gestational diabetes. In about 7 percent of pregnancies in the United States, a woman's blood sugar can get so dangerously high that it can increase her risk for several complications, including pre-eclampsia, infection and labor complications. The good news is that gestational diabetes is highly treatable, but the symptoms can be elusive. Most pregnant women will be screened between 24 and 28 weeks' gestation, but it's extra important to get this test if you have any risk factors — including being obese; non-white; older than 35; or having a history of high blood pressure, heart disease or high cholesterol.

[Everything you need to know about gestational diabetes ]

During your third trimester, consider a few more recommended tests.

Anemia. Your doctor will likely recommend another anemia test around 28 weeks to ensure you haven't developed a severe version of it during your pregnancy, which can increase several risks including significant blood loss during delivery. If you have severe anemia, your baby's development could be affected.

S.T.I.s. Certain high-risk women, such as those who tested positive for an S.T.I. during their first trimesters or who have new sexual partners, will be offered testing for sexually transmitted infections again.

Ask your doctor informed questions.

When considering your prenatal testing options, the experts I spoke with recommended asking your doctor the following:

• What testing is recommended?

• What possible results can I get from these tests?

• When can I expect the results?

• How will I receive the results; through a phone call, doctor's visit or an online patient portal?

• How accurate are the results?

After you've spoken with your physician, you might also mull over testing decisions with your partner or other family members. Here are some questions to consider:

• What conditions am I worried about?

• Does my family have a history of any genetic disorders?

• What am I hoping to get out of testing?

• What will I do with the information I learn?

Determine whether your prenatal testing is covered by insurance.

Routine lab tests are covered by most insurance plans, but coverage can vary for genetic testing. "Patients should always check with their insurance company before having any genetic test," Dr. Rink said. "It is an ever-changing landscape."

For families without insurance or coverage for genetic testing, some companies such as Myriad or Invitae provide discounts or financial assistance, Stevens said. You can find out more about these programs by contacting the billing department of the testing company you use.

When to Worry

If a genetic screening test has detected a high risk for a particular medical condition, you may want to seek out a genetic counselor who can explain the risks and discuss available treatment options. You can ask your doctor to recommend a genetic counselor or find one in your area online.

If you've had a more invasive diagnostic test and experience cramping, spotting, fever, chills or amniotic fluid leakage, contact your health care provider immediately, as these can be signs of an infection or miscarriage.

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Usa Blood Test for Women to Check on Baby Helathes Pregnnacy

Source: https://www.nytimes.com/article/prenatal-blood-tests-guide.html

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