Effexor Linked to Birth Defects of Heart, Skull, Abdomen, and Face

January 7, 2013 — In a recent study, researchers have found associations between the use of Effexor (venlafaxine) during pregnancy and an increased risk of several birth defects affecting the heart, brain, skull, abdomen, and face.

They found statistically significant increased risks of anencephaly, cleft palate, gastroschisis, atrial septal defect, and coarctation of the aorta. The study involved nearly 20,000 women who reported using Effexor during pregnancy in the National Birth Defects Prevention Study (NBDPS).

Effexor belongs to a class of antidepressants called SNRIs (“serotonin norepinephrine reuptake inhibitors”), which have been studied far less than the SSRIs (“selective serotonin reuptake inhibitors”). Both the SNRIs and SSRIs influence serotonin and pass to a developing fetus. Now that this study has been conducted, both the SSRIs and SNRIs have been linked to an increased risk of birth defects of the heart, abdomen, cranium, and more.

The researchers analyzed data collected from women who took Effexor during pregnancy between 1997 and 2007. They looked for higher risks of 24 different birth defects, and they found higher risks of the following defects:

• Anencephaly: This birth defect occurs when the baby is born missing a large portion of its brain and skull.
• Atrial Septal Defect: This is a heart defect that occurs when there are holes in the septal wall between the left and right upper chambers of the heart. It may require surgery shortly after birth.
• Coarctation of the aorta: This is a heart defect that occurs when the aorta is too narrow, and carries too little from the heart into the body.
• Cleft palate: This is an oral-facial birth defect that occurs when the roof of the mouth is split, and may connect to the nose, gums, or throat. It can make feeding very difficult and may require surgical treatment.
• Gastroschisis: This is an abdominal wall defect that occurs when intestines and abdominal organs protrude outside the body.

The researchers suggested that Effexor’s effect on serotonin may help explain why it is associated with so many defects. Several studies have suggested that serotonin plays a role as a signaling molecule during early fetal development, and medications that disrupt normal signaling could increase the risk of a birth defect.

The researchers concluded the study with the following warning:

“Our data suggest that maternal periconceptional use of venlafaxine might be associated with certain birth defects, specifically anencephaly, cleft palate, gastroschisis, and some heart defects, such as ASD secundum or ASD not otherwise specified, and coarctation of the aorta.”