Is Buspar (buspirone) safe to use during pregnancy?

Buspirone (BuSpar) Safety in Pregnancy

Buspirone is classified as FDA Pregnancy Category B and can be used during pregnancy when clearly needed, though data are limited and it should be avoided if clinically possible. 1

FDA Classification and Official Labeling

• Buspirone is FDA Pregnancy Category B, meaning animal reproduction studies showed no fertility impairment or fetal damage at approximately 30 times the maximum recommended human dose in rats and rabbits. 1
• However, adequate and well-controlled studies in pregnant women have not been performed, so buspirone should only be used during pregnancy if clearly needed. 1
• The FDA label explicitly states that "buspirone hydrochloride tablets administration to nursing women should be avoided if clinically possible" due to excretion in rat milk, though human data are lacking. 1

Available Human Safety Data

Malformation Risk

• The most rigorous prospective study (Massachusetts General Hospital National Pregnancy Registry) followed 68 evaluable women with first-trimester buspirone exposure and found zero major malformations among 72 infants (including 4 sets of twins). 2
• This represents the only prospectively ascertained sample of pregnancy outcomes after first-trimester buspirone exposure, though the sample size remains small. 2

Pregnancy Outcomes

• No specific adverse obstetrical outcomes have been definitively linked to buspirone in the limited available data. 2
• The lack of evidence means definite conclusions cannot be made about all risks and benefits of buspirone use in pregnancy. 3

Clinical Decision-Making Algorithm

When a pregnant patient requires anxiolytic therapy:

1. Assess severity of anxiety disorder - Untreated serious psychiatric illness poses significant risks to both mother and child, including tragic outcomes. 3

2. Consider alternative agents first - Given the extremely limited human data for buspirone compared to other anxiolytics, consider medications with more robust safety profiles if clinically appropriate. 3

3. If buspirone is chosen:

   • Use only when clearly needed and benefits outweigh theoretical risks. 1
   • Use the lowest effective dose. 1
   • Avoid during breastfeeding if clinically possible. 1

4. Monitor pregnancy carefully - Though specific monitoring recommendations for buspirone are not established, general principles of high-risk pregnancy monitoring apply. 3

Important Caveats and Pitfalls

• The primary limitation is the paucity of human data - Only one small prospective study exists, making risk assessment difficult. 2
• Animal data, while reassuring, are not always predictive of human response. 1
• Confounding by indication cannot be excluded - The underlying anxiety disorder itself may contribute to adverse outcomes independent of medication exposure. 3
• The absolute risk of malformations, even if present, appears low based on available data. 2
• Discontinuing effective psychiatric treatment during pregnancy may pose greater risks than continuing therapy in cases of serious psychiatric illness. 3