An unplanned pregnancy while taking diet pills can be continued in most cases, but there are some cases where it is not recommended. There are many different kinds of diet pills on the market, and the impact on the fetus cannot be predicted precisely. The first thing you need to do is to take a weight loss pill, which has a lot to do with the time of taking the pill and the composition of the drug. 1. If you take diet pills within two weeks after the formation of a fertilized egg or more than 28 days after your last menstrual period, the drug is highly toxic and may cause the cells in the fetal sac to die, which will have an impact on the growth and development of the fetus, at which point it is recommended to have regular maternity checks and consult your doctor about terminating the pregnancy after problems are found; 2. Drug composition: The composition of diet pills is crucial to the growth and development of the fetus. If the drug ingredients are safe and written that pregnant women can also eat, in most cases there is no effect on the fetus. However, if the diet pills contain a variety of fetal-sensitive ingredients (such as sibutramine, orlistat, etc.), pregnant women taking diet pills can have a greater impact on embryonic development and even cause malformations. Especially in early pregnancy, which is a critical period for embryonic developmental differentiation and organ formation, it may cause miscarriage or fetal malformation. Pregnant women are advised to consult their doctor whether the medication they are taking will pose a risk to the growth and development of the fetus, and if necessary, the pregnancy needs to be terminated. It is recommended to pay attention to good contraception while taking diet pills, and those who are preparing for pregnancy should stop using diet pills for three months before preparing for pregnancy. For women who choose to continue their pregnancy, they should avoid continuing to take diet pills, and other medications should be taken under the guidance of a doctor.