November 20, 2012 — Pristiq (desvenlafaxine), an antidepressant medication, may increase your risk of having a baby with a birth defect if it is taken during the first trimester of pregnancy.
Pristiq treats depression by targeting serotonin and norepinephrine, two neurotransmitters that influence mood and emotions. Serotonin is also very important during fetal development, and any disruption to the fetal serotonin signaling could potentially cause a life-threatening birth defect.
During the first trimester of pregnancy (until the fetus is 12 weeks old), a fertilized egg divides into millions of cells that grow into physical structures. Serotonin appears very early in fetal development. It is an important signaling molecule involved in cell proliferation, differentiation, migration, and death.
When a pregnant woman uses Pristiq, the drug dissolves in her bloodstream and passes to her developing baby through the placenta. Experts do not fully understand how antidepressants influence fetal brain development or physical development. However, some experts have hypothesized that its effects on serotonin provide “biological plausibility for the origin of heart defects.”
The study, which was published in the medical journal Reproductive Toxicology in December 2011, found that serotonin was an important signaling molecule in fetal heart development:
“Serotonin may be particularly important for heart development and evidence suggests that from the time that progenitor heart cells are patterned during the establishment of laterality, to formation of the outflow tract, to myocardial cell differentiation, to septation of the heart chambers, the neurotransmitter may act as an important signaling molecule.”
The researchers claimed that the use of an antidepressant during the first trimester could potentially increase the risk of having a baby with a birth defect.