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Prescription Drugs and Birth Defects

Prescription Drugs and Birth Defects

The Effects of Teratogenic Drugs on a Developing Fetus

undefinedCertain prescription and over-the-counter drugs can present adverse health risks to an unborn baby.  These drugs are categorized as “teratogenic drugs.”  Drugs of this nature often present the most risk in early pregnancy but can affect the developing fetus throughout gestation.  According to the Children's Hospital of Wisconsin around “4 to 5 percent of birth defects are caused by exposure to a teratogen.”

Drugs to Avoid During Pregnancy

There are a number of drugs that are known to interfere with the healthy development of a fetus.  These drugs could cause direct harm to your unborn baby and should not be taken while pregnant.

  • Phenytoin (Dilantin) – used to treat epilepsy and known to cause "Fetal Hydantoin Syndrome."
  • Consumption of Alcohol which affects the central nervous system
  • ACE Inhibitors can increase the risk for fetal malformations throughout pregnancy
  • Acne medication such as Isotretinoin (Accutane) which can cause heart, face and brain deformities of an unborn baby.
  • Warfarin – a commonly used blood thinner known to cause Fetal Warfarin Syndrome (FWS) or warfarin (Coumadin) embryopathy.

Other medications that may cause birth defects if ingested during pregnancy include certain hormones, antibiotics, thyroid medications, and cancer treatments.

It is essential that you consult a medical doctor and pharmacist before taking any medication while pregnant.   The FDA requires the labeling of prescription drugs according to their risk factors during pregnancy.  The FDA Pregnancy Categories are A, B, C, D, and X.  Only Category A drugs have been subjected to "adequate and well-controlled studies" that have "failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters.)  The subsequent categories either have not had adequate studies or have demonstrated potential human fetal risk.

Evaluating the Risks

It is essential that before stopping or starting any prescription drug while pregnant, you seek advice from your treating physician.  It can be dangerous for a person to stop taking a necessary medication.  The risks to the unborn child might be significantly less than they would be to the mother if she stopped taking the drug abruptly.  The most important thing for both the health of the mother and the fetus is that all prescription or over-the-counter medicines taken during pregnancy are disclosed to your midwife or obstetrician.  A licensed medical professional familiar with your medical condition and your pregnancy can advise you on what drugs you should continue to take or recommend a specialist.