Bisoprolol and Pregnancy
Based on the results from animal studies, bisoprolol may not be safe for pregnant women. When the medication was given in high doses to pregnant rats and rabbits, it increased the risk of miscarriages. Due to these potential problems, it is important to talk to your healthcare provider if you are taking bisoprolol and pregnancy occurs.
Bisoprolol fumarate (Zebeta®) is a prescription beta blocker approved to treat high blood pressure. Based on the results of animal studies, this medication may not be safe for use during pregnancy, although the full risks are currently unknown.
The U.S. Food and Drug Administration (FDA) uses a category system to classify the possible risks to a fetus when a specific medicine is taken during pregnancy. Pregnancy Category C is given to medicines that have not been studied in pregnant humans but that do appear to cause harm to the fetus in animal studies. Also, medicines that have not been studied in any pregnant women or animals are automatically given a pregnancy Category C rating.
When given to pregnant rats and rabbits, very high doses of bisoprolol increased the risk of miscarriages. The medication did not appear to increase the risk of birth defects.
However, it is important to note that animals do not always respond to medicines the same way that humans do. Therefore, a pregnancy Category C medicine may be given to a pregnant woman if a healthcare provider believes that the benefits to the woman outweigh any possible risks to the unborn child.
Little human research has been done on the effects of bisoprolol during pregnancy. There is one report of a woman who took bisoprolol (along with a few other medications) when pregnant. Although the baby had numerous birth defects, this one case does not strongly suggest that there is a link between use of this medication and birth defects in humans.
With beta blockers in general, there have been reports of slowed intrauterine growth, small placentas, and birth defects related to the use of beta blockers during pregnancy. There have also been reports of a very low heart rate, low blood sugars, and/or decreased breathing in some newborns whose mothers took beta blockers just before or during childbirth.