What to avoid when trying to conceive

How do the options compare?

The lens is a clinician's: guideline endorsement, pregnancy evidence, dosing, onset, and tolerability. Cost and formulation notes appear where relevant.

• Tobacco, alcohol, marijuana, illegal drugs, and prescription drugs taken for non-medical reasons are the substances ACOG names to stop before pregnancy, linking them to birth defects, low birth weight, preterm birth, and stillbirth; a male partner is advised to stop too, since these can damage sperm cells. 1
• Bring all medications, vitamins, and herbal remedies in their original packaging to the prepregnancy visit, and do not stop a prescription medication before talking with your clinician, since the benefit of continuing may outweigh the risk. 1
• Isotretinoin causes birth defects in 35 percent or more of exposed infants and raises miscarriage risk to as high as 40 percent with early pregnancy use, which is why the iPLEDGE program requires two forms of birth control from one month before through one month after; the guidance is to wait one month after stopping before trying to conceive. 2
• For vitamin A, the recommended dietary allowance is 770 mcg RAE with an upper limit of 3,000 mcg from preformed sources, and the usual advice is to avoid doses above 10,000 IU a day of preformed vitamin A unless a clinician directs otherwise, since intakes above 20,000 IU a day have been linked in some studies to a higher chance of birth defects. 3
• FDA and EPA advise those who are pregnant or breastfeeding to eat 8 to 12 ounces a week of lower-mercury seafood and to skip the highest-mercury fish, a list that includes shark, swordfish, king mackerel, marlin, orange roughy, bigeye tuna, and Gulf of Mexico tilefish. 4
• There is no identified safe amount of alcohol during pregnancy, so the guidance is to avoid all alcohol use once pregnancy is possible, though a single isolated drink is considered much less concerning than heavy or binge drinking. 5

Which option makes sense?

Isotretinoin is the single highest-stakes item to clear before conceiving, with a mandatory one-month wait. Alcohol has no identified safe amount, while high-dose vitamin A, high-mercury fish, and caffeine are all about staying under a specific ceiling rather than avoiding the category entirely.

Disclosure: Pregnancy Smart is a supplement maker. The options compared above sit outside our own product line; this page describes their pregnancy evidence on its own merits.