Is it safe to use selective serotonin reuptake inhibitors (SSRIs) during pregnancy?

SSRI Use During Pregnancy: Safety Assessment

SSRIs can be used during pregnancy when clinically indicated, as the absolute risks of adverse outcomes are generally small and must be weighed against the substantial risks of untreated maternal depression. 1, 2

Key Safety Considerations

Congenital Malformations

• Most SSRIs do not significantly increase the risk of major congenital malformations when confounding by maternal psychiatric illness is properly accounted for. 1, 3

• Paroxetine requires special caution: The FDA classified paroxetine as pregnancy category D in 2005 due to concerns about cardiac malformations, though more recent large cohort studies (nearly 1 million pregnant women) found no definitive link between first-trimester antidepressant use and cardiac malformations. 1

• When restricted to women with documented psychiatric diagnoses (controlling for confounding by indication), the risk of major congenital anomalies (RR 1.04,95% CI 0.95-1.13) and congenital heart defects (RR 1.06,95% CI 0.90-1.26) was not significantly elevated. 3

Obstetric Complications

SSRIs are associated with small absolute increases in several obstetric risks: 1, 2

• Preterm delivery: Antidepressant use may increase risk compared to untreated depression, though the absolute risk remains small. 1

• Persistent pulmonary hypertension of the newborn (PPHN): The FDA revised its 2006 advisory in 2011, stating that conflicting findings make it unclear whether SSRIs cause PPHN. A meta-analysis found a number needed to harm of 286-351 for late pregnancy SSRI exposure. 1

• Pre-eclampsia and postpartum hemorrhage: Small increased risk, though absolute risk remains low. 2

• NICU admissions: Possible increased risk, but often related to neonatal adaptation syndrome rather than serious complications. 2

Neonatal Adaptation Syndrome

Third-trimester SSRI exposure can cause transient neonatal symptoms: 1

• Symptoms include continuous crying, irritability, jitteriness, tremors, hypertonia, tachypnea, feeding difficulty, sleep disturbance, and rarely hypoglycemia or seizures. 1

• Onset ranges from several hours to several days after birth, typically resolving within 1-2 weeks (occasionally up to 4 weeks). 1

• These symptoms represent either serotonin syndrome or SSRI withdrawal, both of which are generally self-limited. 1

Neurodevelopmental Outcomes

Current evidence provides reassurance regarding long-term neurodevelopmental effects: 1, 2

• Converging evidence from multiple study designs suggests that observed associations between prenatal SSRI exposure and neurodevelopmental problems (including autism spectrum disorder and ADHD) are largely due to confounding factors rather than causal effects. 1

• Recent data suggests no increased risk of neurodevelopmental disorders in offspring after accounting for maternal psychiatric illness. 2

• Mixed evidence exists for cognitive outcomes and affective disorders, but methodological limitations prevent definitive conclusions. 2

Miscarriage Risk

Women exposed to SSRIs in early pregnancy have a slightly increased miscarriage rate (12.6% vs 11.1% unexposed, adjusted HR 1.27,95% CI 1.22-1.33). 4

• Critically, women who discontinued SSRIs 3-12 months before pregnancy had a similar increased miscarriage risk (HR 1.24,95% CI 1.18-1.30), suggesting the association is related to underlying maternal illness rather than medication exposure. 4

• Therefore, SSRIs should not be discontinued during pregnancy solely due to fear of miscarriage. 4

Clinical Decision-Making Algorithm

When evaluating SSRI use in pregnancy: 1, 5, 6

1. Assess severity of maternal depression: Untreated depression carries significant risks including premature birth, decreased breastfeeding initiation, and maternal morbidity. 1

2. Consider medication-specific risks:

   • Avoid paroxetine if possible due to historical FDA concerns, though recent data is more reassuring. 1
   • Sertraline and paroxetine are preferred during breastfeeding due to low transfer into breast milk. 1

3. Timing considerations: If SSRI use after 20 weeks of gestation, counsel about small absolute risk of PPHN (NNH 286-351). 1

4. Monitoring recommendations: Offer prenatal ultrasound and fetal echocardiography to detect potential birth defects in women exposed to SSRIs in early pregnancy. 6

5. Do not discontinue treatment solely due to pregnancy: The risk of depression relapse with discontinuation is high, and discontinuation does not eliminate risks associated with underlying maternal illness. 5, 4

Common Pitfalls to Avoid

• Do not assume all observed associations are causal: Most adverse outcomes associated with SSRIs in observational studies are confounded by maternal psychiatric illness and associated risk factors. 1, 3, 5

• Do not discontinue SSRIs abruptly: This increases relapse risk without eliminating pregnancy-related concerns, as underlying maternal illness carries its own risks. 4

• Do not overlook the risks of untreated depression: Depression during pregnancy is associated with premature birth, decreased breastfeeding, and has not been shown to improve with antidepressant discontinuation. 1