Studies have linked the use of SNRI antidepressants during pregnancy to an increased risk of having a baby with a birth defect — including heart defects, cranial defects, intellectual disabilities, Persistent Pulmonary Hypertension of the Newborn, and more. The manufacturer of one of the most popular SNRIs, Pristiq (desvenlafaxine), has warned that birth defects are consistent with a “direct toxic effect” of the drug in an infant.
SNRI Birth Defects
Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs) are medications that are used to treat depression, anxiety disorders, mood disorders, and more. The most popular SNRIs include:
- Pristiq (desvenlafaxine)
- Effexor (venlafaxine)
- Cymbalta (duloxetine)
Unfortunately, several studies have linked antidepressants to an increased risk of birth defects. Most scientific studies have been conducted on SSRI (selective-serotonin reuptake inhibitors) because SSRIs are more widely-used than SNRIs. Because SNRIs and SSRIs both influence serotonin and norepinephrine, there is a possibility that both classes of drugs may have a similar risk of birth defects.
Pristiq and Birth Defects
Pristiq (desvenlafaxine) is an antidepressant that is classified as a “Pregnancy Category C” drug. Studies of Pristiq in animals (rodents and rabbits) have linked it to an increased risk of low fetal birth weight and fetal death of unknown cause (miscarriage, stillbirth).
It is possible that Pristiq could have an adverse effect on a developing human baby, but no studies have been conducted of Pristiq in pregnant women. Due to the possible risk of birth defects, the manufacturer and the FDA warn that Pristiq should only be used if its benefits outweigh any potential risks to a fetus.
The warnings on Pristiq state:
“Neonates exposed to SNRIs (Serotonin and Norepinephrine Reuptake Inhibitors), or SSRIs (Selective Serotonin Reuptake Inhibitors), late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding. Such complications can arise immediately upon delivery.”
SNRIs and Third Trimester Birth Defects
One of the most common complications associated with SNRIs is fetal withdrawal due to drug discontinuation, which is estimated to occur in 30% of infants exposed to an antidepressant until the third trimester. Symptoms may include:
- Poor breathing
- Low oxygen, skin that is blue, clammy
- Difficulty feeding
- Constant crying for several hours
- Convulsions, tremors
- And more
According to the manufacturer “These features are consistent with either a direct toxic effect of SSRIs and SNRIs or, possibly, a drug discontinuation syndrome.”
SNRIs and Birth Defects
More than a dozen studies have linked antidepressants to an increased risk of birth defects, including:
- Heart defects
- Cranial defects (craniosynostosis)
- Abdominal defects (omphalocele, gastroschisis)
- Spinal / neural tube defects
- Oral clefts (cleft lip, cleft palate)
- Persistent Pulmonary Hypertension of the Newborn (PPHN)
- Low birth weight
- Premature birth
- And more