Rationale: Simvastatin is a Category X medication, meaning it has been proven to have a harmful effect on the human fetus and is contraindicated in pregnancy. The risks outweigh the benefits in Category X drugs. Metformin and amoxicillin are Category B drugs, meaning that animal studies do not demonstrate a risk to the fetus, and no well-controlled studies have been done in pregnant women. Gabapentin is a Category C drug, meaning that animal studies demonstrate a risk to the fetus, but it is possible that the benefits outweigh the risks in pregnant women. Very few drugs are tested in pregnant women due to ethical concerns of conducting clinical trials that may expose the fetus to harm.