There are many types of medications used to control high-blood pressure and one of them is ACE inhibitors which has been found to may lead to birth defects even if taken if the first trimester. It has been previously known that the drug was not safe for usage in the second and third semester but researchers found out that taking ACE inhibitors in early pregnancy can also have negative outcomes on the baby.

It was found that there is a three-fold increase in birth defects risk if mothers took ACE inhibitors in the first trimester than in mothers took no blood-pressure medication.

More research is indicated but scientists advise that women should discuss with their doctors which drugs to take if they are planning on getting pregnant in the near future.

Birth effects associated with the intake of Ace inhibitors in early pregnancy are cardiovascular and central nervous system birth defects-both four times higher risk as well as musculoskeletal defects, gastrointestinal problems and urologic defects.
Interestingly, other blood-pressure drugs had no such impacts on the fetuses.

It is not clearly known what causes birth effects with ACE inhibitors intake. These medications inhibit an enzyme, which is present in the fetal heart, kidney and brain while these organs are being formed, and lower high blood pressure that way. Since the drug is interfering with the enzyme function, it is quite possible that it could be interfering with the organ formation as well.