There are no adequate and well-controlled studies investigating metoprolol and pregnancy. The FDA says that metoprolol should be used during pregnancy only if clearly needed. The FDA goes on to explain that tests on laboratory animals show the use of metoprolol can increase the loss of fetuses after egg implantation and decrease neonatal survival.
Because no good studies on metoprolol and pregnancy in humans exist, and because the results of animal studies do not always predict human health, metoprolol should only be used when clearly needed.
Metoprolol and Breastfeeding
Metoprolol is present in very small quantities of breast milk, which means the drug can pass from the mother to the child during breastfeeding. According to the FDA, an infant consuming 1 liter of breast milk a day would receive a dose of less than 1 mg of the metoprolol.
Are beta-blockers safe during pregnancy?
Research shows that beta-blockers are not associated with an increased risk for birth defects or heart problems for the fetus in the first trimester. Though if a beta-blocker is used during pregnancy, fetal growth should be monitored and the newborn should be monitored after delivery for adverse effects such as low heart rate, low blood sugar, and respiratory distress/depression. Beta-blockers may be used in pregnancy and are the second line of treatment for high blood pressure (hypertension) during pregnancy per the American Heart Association.
Can beta-blockers cause miscarriage?
There are no studies that show beta-blockers cause miscarriage.
Does metoprolol cause infertility?
According to the FDA, metoprolol does not cause infertility.
What is the safest blood pressure medication during pregnancy?
The American Heart Association lists methyldopa as the drug of choice when it comes to blood pressure medication during pregnancy, followed by labetalol, long-acting nifedipine, hydralazine, and beta-blockers.