Taking the antidepressant medication Effexor (venlafaxine) during pregnancy may increase your risk of having a baby with anencephaly. This severe, life-threatening birth defect occurs when much of a baby’s brain and skull do not develop. Unfortunately, many women who took Effexor during pregnancy were not aware of the potential risk to their unborn child.
Effexor and Anencephaly
At first, it might not make sense how Effexor (venlafaxine), an antidepressant medication, could be associated with birth defects. Effexor treats major depression and anxiety disorders by affecting levels of two neurotransmitters: serotonin and norepinephrine. In addition to influencing moods and emotions, these neurotransmitters also appear very early in fetal development and work as signaling molecules to form physical structures, including the central nervous system. Medications that influence serotonin, including Effexor, could potentially cause many severe birth defects — especially during the first trimester.
Studies of Effexor and Anencephaly
Effexor was linked to an increased risk of anencephaly in this study, which was published in December 2012 by the medical journal Birth Defects Research. The researchers found a 6.5-fold higher risk of anencephaly associated with maternal use of Effexor during pregnancy, according to data from the National Birth Defects Prevention Study (NBDPS).
What is Anencephaly?
Anencephaly is a congenital birth defect that occurs when a fetus develops without most of its brain and/or skull. The defect occurs during the first month of development. This is when the neural tube normally closes, forming a protective covering around the spinal cord, which allows the rest of the baby’s central nervous system to develop. Anencephaly occurs when the upper portion of the neural tube fails to close, which results in under-development of the brain and skull. This birth defect usually causes severe neurological impairment.