Can a pregnant woman take Prozac (fluoxetine) during pregnancy?

Fluoxetine (Prozac) Use During Pregnancy

Fluoxetine (Prozac) can be used during pregnancy when the benefits outweigh the risks, but pregnant women should be aware of potential third-trimester complications including neonatal adaptation syndrome and a small increased risk of persistent pulmonary hypertension of the newborn.

Risks Associated with Fluoxetine During Pregnancy

First and Second Trimester Exposure

• No significant increase in risk of spontaneous pregnancy loss compared to women not taking fluoxetine (10.5% vs. 9.1%) 1
• No significant difference in major structural anomalies (5.5% vs. 4.0%) 1
• The FDA label indicates no evidence of teratogenicity in animal studies 2

Third Trimester Exposure

• Increased risk of neonatal adaptation syndrome, which includes:

  • Respiratory distress, cyanosis, apnea
  • Seizures, temperature instability
  • Feeding difficulties, vomiting, hypoglycemia
  • Hypotonia, hypertonia, hyperreflexia, tremor, jitteriness, irritability 2

• Compared to first/second trimester exposure only, third trimester exposure is associated with:

  • Higher rates of premature delivery (relative risk 4.8)
  • Increased admission to special-care nurseries (relative risk 2.6)
  • Poor neonatal adaptation (relative risk 8.7)
  • Lower birth weight and shorter birth length 1

• Possible increased risk for persistent pulmonary hypertension of the newborn (PPHN) with exposure after 20 weeks gestation 3, 2

  • Number needed to harm: 286-351 3

Breastfeeding Considerations

• Fluoxetine is excreted in breast milk 2
• Infant exposure from breast milk is estimated at 2.4% to 3.8% of the maternal weight-adjusted daily dose 4
• Some case reports of adverse effects in nursing infants including crying, sleep disturbance, vomiting, and watery stools 2

Decision-Making Algorithm

1. Assess severity of maternal depression

   • Untreated depression during pregnancy is associated with premature birth and decreased initiation of breastfeeding 3

2. Consider gestational age

   • First/second trimester: Lower risk of neonatal complications
   • Third trimester: Higher risk of neonatal adaptation syndrome and PPHN

3. Evaluate alternatives

   • If starting treatment during pregnancy, consider SSRIs with shorter half-lives
   • If patient is stable on fluoxetine, weigh risks of changing medication versus continuing

4. If continuing fluoxetine in third trimester:

   • Prepare for potential neonatal complications
   • Consider gradual dose reduction before delivery if clinically appropriate 2
   • Ensure neonatal monitoring after birth

Important Clinical Considerations

• Fluoxetine has a long half-life, which may contribute to prolonged neonatal effects
• Pregnancy may alter fluoxetine metabolism - one study showed 2.4-fold higher norfluoxetine/fluoxetine ratio during late pregnancy compared to postpartum 4
• At delivery, infant plasma concentrations of fluoxetine and norfluoxetine were 65% and 72% of maternal levels, respectively 4

Common Pitfalls to Avoid

1. Abrupt discontinuation during pregnancy

   • May increase risk of maternal depression relapse
   • Women who discontinue antidepressants during pregnancy are more likely to experience relapse of major depression 2

2. Ignoring signs of neonatal adaptation syndrome

   • Symptoms can arise immediately upon delivery and may require prolonged hospitalization, respiratory support, and tube feeding 2

3. Failing to prepare the pediatric team

   • Ensure neonatologists are aware of maternal fluoxetine use, especially with third trimester exposure

4. Overlooking maternal depression

   • Untreated maternal depression carries its own risks to both mother and child

While fluoxetine use during pregnancy carries some risks, particularly in the third trimester, these must be balanced against the risks of untreated depression. The decision should be made with careful consideration of the mother's mental health needs and the potential risks to the developing fetus.