Motherisk Update: Taking bisphosphonates during pregnancy

Question. Several of my female patients take bisphosphonates for low bone mineral density (BMD). Two of them are of reproductive age. Are these drugs safe during pregnancy? Answer. Very little is currently known about the effects of bisphosphonates on human pregnancy. There have been only two reports of bisphosphonate use during late pregnancy. Animal studies suggest that biphosphonates cross the placenta and that the effect is an extension of the expected pharmacologic effect of bisphosphonates on both fetus and mother. Risks and benefits should be carefully weighed.