Can taking diet pills while trying to get pregnant or in early pregnancy cause harm to the baby, or cause problems trying to concive?

Yes: Whenever you are actually trying to get pregnant, it is important not to take any medication (over-the-counter or prescription) without checking with your doctor. Some very common medicines can have adverse affects during pregnancy. It is better to be safe and avoid unnecessary medications at this time.

Yes: Many diet pills contain substances like Ephedrine that constrict blood vessels. Since the fetal brain starts forming 3 weeks after conception & other organs shortly after, there is a risk, as there is with sudafed. Take folate (folic acid) for at least 3 months before conceiving & stop all otc medicines, tobacco, alcohol & drugs at the same time. Discuss your prescription & otc medications with your ob.