First Trimester Tests During Pregnancy: Everything You Need to Know

When I first became pregnant with my twins, I remember being so worried about whether I’d have a healthy pregnancy. I had already had one miscarriage, so I went into my 6-week ultrasound with so much anxiety. To my relief, the doctor saw one heartbeat…and then another! I breathed a sigh of relief…and then went into panic mode…and then was just thrilled to know that I had two babies on the way.

Of course, that was just the beginning. Over the next several weeks, I had to have a number of blood tests, including several to rule out genetic diseases, and high-tech ultrasounds to check on the health of my identical twins, since my pregnancy was considered high-risk.


At 12 weeks, all of our tests came back normal, and I was psyched to be able to share our good news with friends and family. But, man, those weeks waiting on test results were stressful, for sure. That was over five years ago though, and medicine has come a long way. So pregnant women, even those over 35, don’t necessarily need to go through risky procedures like an amniocentesis or CVS. Still, there are some essential tests that every expectant mother should have. Here is what’s recommended, according to Yvonne Bohn, MD, a Santa Monica-based ob-gyn at Los Angeles Obstetricians and Gynecologists.

6 to 8 Weeks…

1. First Prenatal Check-Up

At your first prenatal visit, which usually occurs between 6 and 8 weeks of pregnancy, your ob-gyn will give you a typical checkup, which will include a breast exam and pap smear. She’ll take urine and blood samples to screen for infections, including sexually transmitted diseases, as well as identify your blood type to make sure it is compatible with the baby. She’ll ask about your vaccination history to ensure your inoculations are up to date. And, she’ll perform an ultrasound to check for your baby’s heartbeat, gauge just how far along you are, and rule out a miscarriage or ectopic pregnancy.

2. Genetic Panel 

Even if you don’t have a genetic disease, you may be a carrier of one. If your husband is also a carrier, your baby has a 1 in 4 chance of actually having that disease. Certain ethnic groups such as Ashkenazi Jewish women, African-American women, and Asian women are more prone to specific genetic disorders, so they will routinely get a blood test at their first visit (often preconception even), which screens for around 200 genetic diseases. These days though, this blood test is so inexpensive that many doctors routinely run it on all patients, regardless of ethnicity. “Don’t freak out too much at the results,” says Dr. Bohn. “Since we test for so many diseases now, it’s very likely that you might be a carrier for one. But it would be very rare for your partner to also be a carrier, so the likelihood is that your child will be just fine.”

Additional Tests May Include:

Thyroid check: An underactive thyroid can harm your baby, so many doctors will want a blood test to ensure you have adequate amounts of thyroid hormone.

Diabetic screening:
If you’re overweight, have a family history of diabetes, or had gestational diabetes in previous pregnancies, your doctor may want to check your initial glucose levels through a blood test. (Every pregnant mom has a blood glucose screening during the second trimester, since some moms can develop gestational diabetes.)

9 to 10 Weeks…

3. NIPT (Non-Invasive Perinatal Testing)

Just a few years ago, first trimester tests involved a finger prick blood test, combined with an ultrasound, to rule out chromosomal disorders, particularly Downs’ Syndrome. “These days though, genetic testing has really evolved, and it’s gotten cheaper as well,” says Dr. Bohn. “With NIPT, like Maternit21, a mom of any age can get a blood test done as early as 10 weeks, which can tell you with 99 percent certainty whether the baby has any extra or missing chromosomes that can lead to Downs Syndrome, and other, more severe birth defects.” If the results come back favorably, it eliminates the need for a mother to get risky, invasive procedures like amnio or CVS. It’ll also reveal the sex of your baby very early on in the pregnancy, so you can start picking out names ASAP. Although more and more doctors are routinely offering the test to all women, if yours doesn’t suggest it, just ask. Some insurance companies may not fully cover it for low-risk women, so you may want to check with your provider first.

11 to 13 Weeks…

4. First Trimester Ultrasound

Around 11.5 to 13.5 weeks, you will be sent for a 3D or 4D ultrasound, a high-tech scan that allows the doctor to get a really good look at all of those growing baby parts. If you were not offered NIPT, this is when they will measure the back of the baby’s neck, called the nucal fold. That number, along with the results from a first trimester blood test, can tell you the risk of your baby having Downs Syndrome or other chromosomal disorders. 

Additional tests may include:

CVS: If your blood screening comes back positive for any chromosomal abnormalities, your doctor may recommend a chorionic villus sampling (CVS), which is the only way to rule out a disorder with absolute certainty. “In this procedure, a doctor goes through the cervix or the abdomen to take a small sample of fetal tissue from the placenta,” explains Dr. Bohn. “That will give you a fuller picture of all of the chromosomes and determine if there is an abnormality.” This test is usually given between 11 to 13 weeks. Unfortunately though, it does slightly increase your risk of having a miscarriage. It’s considered more risky than an amnio, which is performed in the second trimester, but because it happens so early on, it gives a mother more time to plan.

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