Placental Transfer of SSRI and SNRI Antidepressants and Effects on the Neonate

Introduction: We investigated placental transfer and neurobehavioural effects in neonates exposed to citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine or sertraline (SSRI's), or to venlafaxine (an SNRI). Methods: Women receiving antidepressants during pregnancy and their neonates were studied. Cord and maternal drug concentrations were measured at birth and in the neonates plasma on day 3. Neonates were also assessed using a range of neurobehavioral tests and compared to controls. Results: Median cord/maternal distribution ratio was 0.7-0.86 (range) for SSRIs, 0.72 for the SNRI venlafaxine and 1.08 for the O-desmethyl metabolite. Neonatal abstinence scores were significantly higher (p<0.05) in exposed infants than controls on day 1. Brazelton scores for habituation, social-interactive, motor and autonomic clusters, and serotonin scores were significantly greater (p < 0.05) in exposed infants. Discussion: Transfer of SSRIs and SNRIs across the placenta was substantial. Neonates developed mild behavioral symptoms in the early perinatal period but these were self-limiting and similar for both SSRIs and the SNRI venlafaxine.