Early pregnancy is when your baby’s major organs, brain, and spinal cord are forming, which makes the first trimester the most sensitive window for avoiding things that could interfere with development. The list of what to skip or limit covers food, drinks, medications, skincare, physical activities, and everyday household exposures. Here’s what actually matters and why.
Alcohol Has No Safe Threshold
No amount of alcohol has been established as safe during pregnancy. The CDC and every major obstetric organization recommend zero alcohol if you’re pregnant or planning to become pregnant. Alcohol crosses the placenta freely, and because the first trimester is when the brain and nervous system are taking shape, even small exposures carry risk for what’s collectively known as fetal alcohol spectrum disorder. This isn’t a case where moderation applies. The guidance is straightforward: none.
Foods That Carry Infection Risk
Two infections pose outsized danger in early pregnancy: listeriosis and toxoplasmosis. Both can cause miscarriage or serious developmental problems, and both come from foods that might seem perfectly ordinary.
For listeria, the FDA specifically flags these foods to avoid:
- Deli meats, hot dogs, and luncheon meats unless reheated until steaming hot
- Soft cheeses made from unpasteurized milk, including queso fresco, queso blanco, and requesón (even pasteurized versions of these fresh-style cheeses carry risk)
- Unpasteurized (raw) milk and any foods made with it
- Smoked seafood from the refrigerated section (shelf-stable canned versions are fine)
- Raw sprouts of any kind
Listeria is unusual because it grows at refrigerator temperatures, so foods that look and smell normal can still be contaminated. Cooking to steaming temperatures kills the bacteria, which is why reheating deli meats works.
For toxoplasmosis, avoid raw or undercooked meat, especially lamb, pork, and venison. Wash all fruits and vegetables thoroughly, since soil can harbor the parasite.
High-Mercury Fish to Skip Entirely
Fish is actually encouraged during pregnancy for its omega-3 content, but seven species contain mercury levels high enough to harm a developing nervous system. The FDA says to avoid these completely: king mackerel, marlin, orange roughy, shark, swordfish, Gulf of Mexico tilefish, and bigeye tuna.
Low-mercury fish like salmon, sardines, shrimp, and tilapia are safe and beneficial. If you’re pregnant, aim for 8 to 12 ounces per week (two to three servings, where one serving is roughly the size of your palm). Stick to the FDA’s “Best Choices” category and you’ll get the nutritional benefits without the mercury exposure.
Caffeine: Keep It Under 200 mg
You don’t have to quit coffee entirely, but the American College of Obstetricians and Gynecologists recommends capping intake at 200 mg per day. That’s roughly one 12-ounce cup of brewed coffee. The World Health Organization sets the limit slightly higher at 300 mg, but consistently exceeding 200 mg per day is associated with increased risks.
Above 300 mg daily, the data gets more concerning. Research links that level to lower birth weight, higher risk of preterm birth, and even a 94% increased risk of preterm birth in the second trimester for those in the highest intake group. Caffeine also hides in tea, chocolate, energy drinks, and some sodas, so it adds up faster than you might expect.
Medications to Be Cautious About
The most important over-the-counter medications to avoid in early pregnancy are NSAIDs: ibuprofen (Advil, Motrin), naproxen (Aleve), and aspirin. Acetaminophen (Tylenol) is generally considered the safer option for pain and fever during pregnancy, though you should still use the lowest effective dose.
One of the more alarming findings from CDC research is that among the 54 most commonly used medications in the first trimester, only two had sufficient data to properly assess their risk to a developing fetus. That gap means the safest approach is to check with your provider before taking anything, including supplements, herbal remedies, and common cold medications like those containing pseudoephedrine.
Skincare Ingredients to Remove From Your Routine
Two ingredients stand out as ones to stop using when you find out you’re pregnant. Topical retinoids (tretinoin, retinol, adapalene) are related to vitamin A derivatives known to cause birth defects when taken orally. While prospective studies of small groups haven’t confirmed the same risk from skin creams, troubling case reports exist, and the current recommendation is to avoid them until larger safety studies are completed.
Hydroquinone, a common skin-lightening ingredient, has a systemic absorption rate of 35% to 45%, meaning a significant amount enters your bloodstream through the skin. That’s far higher than most topical products. Limited data haven’t shown increased risk, but the high absorption rate means it’s best to stop using it during pregnancy.
Most other skincare products, including sunscreens, gentle cleansers, and moisturizers, act locally on the skin and produce minimal levels in the bloodstream.
Hot Tubs and Saunas
Raising your core body temperature above 38.9°C (about 102°F) during early pregnancy has been linked to neural tube defects, which are serious problems with brain and spinal cord development. Research on hot tub use found that women’s temperatures didn’t reach that danger zone before 10 to 15 minutes in a typical hot tub (depending on the water temperature). So a brief dip is likely low-risk, but prolonged soaking is not.
In saunas, none of the women studied were able to tolerate staying long enough for their temperature to reach dangerous levels. Still, the safest approach in the first trimester is to limit time in hot tubs to under 10 minutes and avoid very hot baths where you can’t easily regulate your temperature.
Exercise: What’s Safe and What’s Not
Exercise itself is not something to avoid. Staying active during pregnancy is beneficial. What changes is the type of activity. The NHS specifically recommends avoiding or being very cautious with:
- Sports with fall risk: horse riding, downhill skiing, ice hockey, gymnastics, and cycling
- Contact sports: kickboxing, judo, squash, or anything where you could take a blow to the abdomen
Walking, swimming, prenatal yoga, and low-impact strength training are all considered safe throughout pregnancy for most people. The concern isn’t exertion itself but the risk of impact or falls that could harm the pregnancy.
Cat Litter and Toxoplasmosis
Cats can carry the parasite that causes toxoplasmosis, and they shed it in their feces. You don’t need to rehome your cat, but the CDC recommends that pregnant women avoid changing cat litter if possible. If no one else can do it, wear disposable gloves and wash your hands thoroughly afterward. The parasite takes one to five days after being shed to become infectious, so changing the litter daily reduces risk significantly.
Gardening is another overlooked route of exposure, since outdoor cats use garden soil. Wear gloves when working in soil and wash your hands when you come inside.
Cleaning Products and Chemical Fumes
Household cleaning products contain a mix of irritants and sensitizers, including bleach, solvents, fragrances, and compounds called phthalates. Many of these chemicals are small enough to cross the placenta. Research has found associations between occupational exposure to cleaning chemicals during pregnancy and increased risk of respiratory problems in children.
You don’t need to stop cleaning, but practical steps help: use products in well-ventilated rooms (open windows, turn on fans), wear gloves, avoid mixing cleaning products (especially bleach with ammonia-based cleaners), and consider switching to fragrance-free or simpler formulations. If you can smell strong fumes, you’re inhaling chemicals that are better avoided in concentrated amounts during the first trimester.
Smoking and Secondhand Smoke
Nicotine restricts blood flow to the placenta, and the carbon monoxide in cigarette smoke reduces how much oxygen reaches your baby. Smoking during pregnancy increases the risk of miscarriage, preterm birth, low birth weight, and placental complications. Secondhand smoke carries similar, though reduced, risks. Vaping products also deliver nicotine and are not considered a safe alternative during pregnancy. If you smoke, early pregnancy is the most impactful time to stop, since the first trimester is when reduced blood flow does the most developmental damage.