The earliest weeks of pregnancy are when your baby’s brain, spinal cord, and heart begin forming, so the steps you take now have an outsized impact. Most of the important actions fall into a few categories: starting the right supplements, scheduling your first prenatal visit, adjusting your diet and environment, and staying physically active. Here’s what to prioritize.
Start Folic Acid Right Away
Folic acid is the single most important supplement in early pregnancy. It protects against neural tube defects, which are serious problems with the brain and spinal cord that develop in the first few weeks, often before you even know you’re pregnant. The CDC recommends 400 micrograms (mcg) daily for all women who could become pregnant. If you’ve had a previous pregnancy affected by a neural tube defect, the recommendation jumps to 4,000 mcg daily, starting at least one month before conception and continuing through the first three months.
Most prenatal vitamins contain 400 to 800 mcg of folic acid along with iron and other nutrients you’ll need throughout pregnancy. If you haven’t already been taking one, start as soon as you get a positive test.
Schedule Your First Prenatal Visit
Call your doctor or midwife as soon as you find out you’re pregnant to set up your first appointment. At that visit, expect a thorough round of baseline tests: blood work to check your blood type and Rh status, hemoglobin levels, and immunity to infections like rubella and chickenpox. You’ll also be screened for hepatitis B, syphilis, gonorrhea, chlamydia, and HIV. A urine sample checks for bladder or urinary tract infections, which are more common in pregnancy and can cause complications if untreated.
Your provider will likely discuss genetic screening options as well, which can include blood tests or an ultrasound to check for conditions like Down syndrome. You may also have a physical exam, breast exam, and pelvic exam. Bring a list of any medications or supplements you’re currently taking, since some need to be stopped or swapped.
Foods to Avoid in the First Trimester
Pregnancy suppresses parts of your immune system, which makes you significantly more vulnerable to certain foodborne infections. Pregnant women are 10 times more likely to get a Listeria infection than the general population, and Listeria can cause miscarriage or stillbirth even when you feel only mildly ill.
The foods that carry the most risk:
- Deli meats and hot dogs unless heated until steaming. This includes cold cuts, fermented sausages, and refrigerated pâté.
- Soft cheeses made from unpasteurized milk, such as queso fresco, brie, camembert, and blue cheese. Even pasteurized queso fresco-type cheeses carry risk because of how they’re made.
- Raw or undercooked eggs, including homemade Caesar dressing, raw cookie dough, and runny yolks.
- Raw or undercooked seafood and meat, including sushi, sashimi, ceviche, and rare steaks.
- Refrigerated smoked seafood labeled as lox, nova-style, kippered, or smoked (unless it’s in a cooked dish).
- High-mercury fish like shark, swordfish, king mackerel, and tilefish. These can harm your baby’s developing nervous system.
- Unpasteurized milk, juice, or cider.
- Raw sprouts such as alfalfa and bean sprouts.
- Premade deli salads like potato salad, chicken salad, and coleslaw from a deli counter.
Wash all fresh fruits and vegetables thoroughly before eating, and don’t leave cut melon sitting out for more than two hours.
Limit Caffeine
You don’t have to give up coffee entirely. The World Health Organization recommends that pregnant women with high caffeine intake (more than 300 mg per day) reduce their consumption to lower the risk of pregnancy loss and low birth weight. For reference, a typical 8-ounce cup of brewed coffee contains about 95 mg of caffeine, so two to three cups a day generally falls within that range. Tea, soda, chocolate, and energy drinks all contribute to your daily total.
Know Which Medications to Avoid
Common over-the-counter pain relievers called NSAIDs, which include ibuprofen (Advil, Motrin), naproxen (Aleve), and aspirin, require caution during pregnancy. The FDA warns against using NSAIDs at 20 weeks or later because they can cause kidney problems in the baby and dangerously low amniotic fluid levels. Even in early pregnancy, many providers recommend avoiding them unless specifically directed otherwise. The one exception is low-dose aspirin (81 mg), which is sometimes prescribed for specific pregnancy-related conditions.
Acetaminophen (Tylenol) is generally considered the safer choice for pain and fever during pregnancy, but check with your provider about any medication, including herbal supplements, before taking it.
Protect Yourself From Toxoplasmosis
Toxoplasmosis is a parasitic infection that can cause serious harm to a developing baby. The most common sources are undercooked meat and cat feces. If you have a cat, have someone else handle the litter box. If that’s not possible, wear disposable gloves and wash your hands thoroughly afterward. Change the litter daily, because the parasite doesn’t become infectious until one to five days after it’s shed.
Wear gloves when gardening or handling sandbox sand, since outdoor cats use soil as a litter box. Keep your cat indoors, feed it only commercial food (never raw meat), and avoid adopting a new cat while pregnant.
Stay Physically Active
Exercise during early pregnancy is not only safe for most women, it’s actively beneficial. Current guidelines recommend at least 150 minutes of moderate-intensity aerobic activity per week throughout pregnancy. That works out to about 30 minutes on most days. Walking, swimming, stationary cycling, and prenatal yoga all count.
If you were already doing vigorous exercise before pregnancy, like running or strength training, you can generally continue. A study of 300 women who started cycling three times a week in their first trimester found they had a significantly lower rate of gestational diabetes and less weight gain compared to women who didn’t exercise. The key is listening to your body: if something feels wrong, scale back, and avoid contact sports or activities with a high fall risk.
Managing Morning Sickness
Nausea and vomiting affect the majority of women in the first trimester, typically peaking between weeks 8 and 10. For mild cases, eating small, frequent meals and keeping crackers by your bed can help. Ginger tea or ginger supplements work for some women.
If nausea is more persistent, a combination of vitamin B6 and an antihistamine called doxylamine is the standard first-line treatment. It’s available by prescription as a delayed-release tablet, typically starting with two tablets at bedtime, with the option to add a morning dose if symptoms persist through the afternoon. Talk to your provider if you can’t keep water down for more than 8 hours or food down for more than 24 hours, as severe nausea can lead to dehydration that requires treatment.
What’s Happening to Your Baby
Even though you can’t feel anything yet, development moves remarkably fast. By week 5, the neural tube, which becomes the brain and spinal cord, is forming. A tiny cluster of cells that will become the heart starts to pulse, beating about 110 times per minute by the end of that week. By week 6, small buds appear that will grow into arms and legs. By the end of the first trimester at 12 weeks, all major organ systems have begun forming, and the embryo is officially called a fetus.
This rapid development is exactly why the first trimester matters so much. The folic acid you take, the infections you avoid, and the toxins you steer clear of all have their greatest impact during these weeks, when the basic architecture of your baby’s body is being laid down.
Warning Signs That Need Immediate Attention
Some symptoms in early pregnancy signal a potentially serious problem like ectopic pregnancy or miscarriage. Seek medical care right away if you experience sharp or severe belly pain that doesn’t go away or gets worse over time, especially if it comes with shoulder or back pain. Vaginal bleeding heavier than light spotting, or fluid leaking from your vagina, also warrants an immediate call.
Nausea is normal, but there’s a line between typical morning sickness and something more concerning. If you’re unable to keep any fluids down for more than 8 hours, or if you faint, experience ongoing dizziness, or have gaps in memory, those are signs to get help quickly.