More than a dozen studies have linked antidepressants to an increased risk of birth defects. Unfortunately, many women were unaware of this risk before they took an antidepressant during pregnancy.
Antidepressants are medications that are used to treat mood disorders, including major depressive disorder, panic, anxiety, obsessive-compulsive disorder, and more.
There are three major classes of antidepressants:
- SSRIs (selective-serotonin reuptake inhibitors): Prozac (fluoxetine), Zoloft (sertraline), Celexa (citalopram), Lexapro (escitalopram), and more.
- SNRIs (serotonin-norepinephrine reuptake inhibitors): Pristiq (desvenlafaxine), Effexor (venlafaxine), Cymbalta (duloxetine), and more.
- MAOIs (monoamine oxidase inhibitors): Nardil (phenelzine), Marplan (isocarboxazid), Parnate (tranylcypromine)
Studies of Antidepressants and Birth Defects
Most studies of antidepressants and birth defects have focused on the SSRI class, because these are the most widely-used antidepressants. However, it is possible that birth defects associated with SSRIs also apply to SNRIs because both medications influence serotonin and pass to a developing fetus during pregnancy.
It is also important to note that no well-controlled studies have been conducted of antidepressants in pregnant women. This is because it would be unethical to randomly assign pregnant women an antidepressant or a placebo. Therefore, researchers can only look for correlations between antidepressants and birth defects after the baby has already been born.
According to this study from 2006, several studies have found associations between antidepressants and birth defects:
- Using an SSRI during the third trimester is associated with a 20-30% risk that the child will be born with withdrawal symptoms (vomiting, irritability, convulsions, seizures, respiratory problems), which may indicate drug toxicity in a fetus.
- A Danish study involving 1054 pregnant women found a 40% increased risk of birth defects, and a 60% increased risk of heart defects.
- An American retrospective study found that babies exposed to the SSRI antidepressant Paxil (paroxetine) found that 4% had birth defects and 2% had heart defects.
- A study based on an American registry of birth defects found a 3-fold increased risk of omphalocele, a type of abdominal birth defect, and a 1.8-fold increased risk of craniosynostosis, a cranial birth defect.
This study presented a plausible mechanism by which antidepressants could increase the risk of birth defects. Antidepressants pass to a developing fetus and influence serotonin, which plays an important role in early fetal cell proliferation, migration, differentiation, and death — especially in the heart. According to the researchers, medications that disruption serotonin signaling could potentially cause a birth defect.
Antidepressant Birth Defects
Mothers who used an antidepressant during pregnancy may have a higher risk of having a baby with the following birth defects:
- Heart defects
- PPHN (Persistent Pulmonary Hypertension of the Newborn)
- Neural tube defects (spina bifida)
- Skull defects (craniosynostosis)
- Abdominal wall defects (omphalocele, gastroschisis)
- Cleft palate, cleft lip
- Premature birth, miscarriage
- Fetal withdrawal at birth
- And more