What Every Pregnant Woman Should Know About Nutrition, Exercise and Prenatal Screenings

Pregnancy comes with an overwhelming amount of advice, much of it contradictory, some of it outdated and almost all of it unsolicited. Knowing what actually matters from a clinical standpoint can be hard to sort out, especially for first-time parents navigating a flood of information from every direction. Naima Bridges, M.D., an ob-gyn and medical adviser at BillionToOne, cuts through the noise with straightforward guidance on how to eat, how to stay active and which prenatal visits and screenings deserve the most attention.

When it comes to nutrition, supplements and exercise during pregnancy, what are the most important things women should be doing, and what are the most common mistakes you see patients make that are worth addressing early?

Naima Bridges, M.D.: A well-balanced diet is critical. Often, women can't eat as much as they could prior to pregnancy because the progesterone hormone causes them to feel more full. Plus, the larger the uterus gets, the higher it pushes your intestines up into your stomach, so you don't have the same capacity to maintain the same eating habits that you did prior to pregnancy. Instead, I typically recommend that pregnant women have five small meals a day: a small breakfast, a snack, a small lunch, a snack and then a small dinner. This helps avoid feeling stuffed or nauseous and also keeps blood sugar levels more even throughout the day.

Daily prenatal vitamins are important as well, because those nutrients actively support a successful pregnancy.

I'm a big advocate for exercise during pregnancy. One of the most important things we can do in pregnancy is to keep moving. A big misconception is that once you get pregnant, you have to stop exercising. My patients who remain active through their pregnancy typically do better throughout their pregnancy in terms of their blood pressure, their blood sugar, their labor and their healing and recovery process. There's a wide range of the types of exercise a pregnant woman can do, whether that's going on a daily walk or actually going to the gym to lift weights, run, use the elliptical, StairMaster or cycling. All of these activities may be possibilities in pregnancy that can continue until they are no longer comfortable, unless the patient's physician has advised against it.

With so many appointments on the pregnancy calendar, which screenings and visits are the ones you consider truly critical, and why might a woman regret skipping them?

NB: Ob-gyns often first see patients between 6 to 8 weeks to run baseline labs, get baseline vitals and do an ultrasound. The lab work gives us insight into the patient's medical history; things like blood sugar abnormalities or blood pressure abnormalities. The ultrasound tells us important details about the health of the pregnancy—are there multiples/twins, is it an ectopic [outside the uterus] pregnancy or an anembryonic pregnancy/miscarriage? That first visit is important for creating a clear road map for the rest of your pregnancy and guiding all subsequent decisions. From there, providers typically will see patients every 4 weeks or so.

Between the first and second visit [between 8 and 12 weeks] is the most important time to look at doing prenatal screening to look at the baby's DNA to get a better look at their health and determine if any follow-up is needed sooner in pregnancy. The American College of Obstetricians and Gynecologists recommends that all pregnant patients be screened for certain inherited conditions, including cystic fibrosis, sickle cell disease and spinal muscular atrophy. These conditions are more common than most people realize, and carriers typically have no symptoms. One of the most common genetic screening tests offered is called a noninvasive prenatal test [NIPT], which is a simple blood test that can be done as early as 9 weeks. It screens for certain chromosomal conditions, and, depending on your situation, your provider may also recommend collecting information about your baby's RhD or antigen status, which, for some patients, can be important for preventing complications later in pregnancy. You may also be offered screening for recessive conditions, like through Unity Screen, that can tell you if you are a carrier for certain inherited conditions [such as sickle cell disease] that can impact your baby's risk of being affected.

Typically, if results from the NIPT or carrier test come back positive for any condition, the ob-gyn will refer those patients to a high-risk specialist. Ob-gyns rely on those specialists to go through some of the treatment modalities and further diagnostic testing modalities. These patients are also likely to be paired with a genetic counselor. Together, this team will determine the next best steps and whether further testing is needed. It's important to remember that your ob-gyn is part of a larger care team working together to provide an extra set of eyes and more data on some of the additional testing that may need to be done. Some of that is learning more about the mother’s and father's histories; some of it is more diagnostic testing to better confirm some of the information received through the preliminary screening results. That can be done noninvasively from a simple maternal blood draw with Unity Confirm or through procedures like a chorionic villus sampling or amniocentesis that take fluid from around the baby.