Researchers have found, after reviewing a database containing 3 million pregnancies, that 1 in 16 women were exposed to teratogenic drugs.
The study, published in the American Journal of Obstetrics and Gynecology, highlights the need for women and their providers to carefully examine medications taken during pregnancy.
A teratogen is a substance that interferes with the normal development of a foetus. Hundreds of such drugs have been identified, including medications to treat seizures, migraines, obesity, acne, hypertension, bipolar disease and cancer.
University of Florida researchers investigated more than 200 teratogenic drugs and evaluated their exposure among 3.4 million pregnancies identified in a national private insurance database from 2006 to 2017. Prenatal exposure was defined by the mother taking at least one teratogenic drug during pregnancy.
The researchers divided drugs into two classes based upon their known teratogenic effect. About 140 drugs were known to have definite teratogenic effects, with another 65 identified as having potential teratogenic effects. The proportion of pregnancies with exposure to definite teratogens decreased slightly over the 12-year study period from 1.9% to 1.2%, while exposures for potential teratogens increased from 3.4% to 5.3%.
“While declining exposure rates among teratogenic drugs with definite risk are encouraging, the rising prenatal exposure to drugs with potential risk calls for more assessment,” study author Professor Almut Winterstein, PhD, RPh. “To have 1 in 16 women and their unborn baby exposed to a teratogenic medication is simply too high, and we must identify strategies to improve pregnancy outcomes.”
The study also examined age and risk for prenatal exposure to teratogenic drugs and found teenagers and women in their 40s had the greatest risk. Both groups are known to have more unintended pregnancies and the drug exposure may have been accidental, which points to the need for more information about effective birth control and family planning when using teratogenic drugs.
The researchers were especially interested in prenatal exposure during more recent years, following the enactment of FDA requirements for risk mitigation strategies. Those are designed to reinforce safe medication-use behaviors, such as a pregnancy test before a teratogenic drug is started, and only a few medications require this extra safety precaution.
The 12 drugs with mitigation protocols in the study were found to be used infrequently and contributed to only a small portion of prenatal exposures. More research and regulatory action are needed to optimise the use of medications during pregnancy, the researchers concluded.
“There is much to do to address the evidence available regarding the risk-benefit of many drugs during pregnancy, and the availability of adequate risk-mitigation programs that ensure pregnancies are not unnecessarily exposed to teratogenic drugs,” Prof Winterstein said. “In the meantime, women and their providers must rely on the written information that is provided about the teratogenic risk for drugs during pregnancy.”
Source: University of Florida
