Buspirone has not been proven harmful during pregnancy, but the honest answer is that very little human data exists to confirm it’s completely safe. The FDA assigned it Pregnancy Category B, meaning animal studies at doses roughly 30 times the maximum human dose showed no fetal damage, yet no well-controlled studies have been done in pregnant women. In practice, this puts buspirone in a gray zone: no clear red flags, but not enough evidence for firm reassurance either.
What the Existing Human Data Shows
The largest published dataset comes from the Massachusetts General Hospital National Pregnancy Registry for Psychiatric Medications. As of early 2022, 97 women who took buspirone during their first trimester had enrolled. Of those, 68 had complete follow-up data, producing 72 infants (four sets of twins). Among those 72 infants, zero major malformations were observed.
That’s encouraging, but 72 infants is a tiny sample. To put it in perspective, if a medication caused birth defects in 1 out of every 100 exposures, a study this size could easily miss it. Researchers acknowledged this limitation directly. No study has yet examined whether buspirone affects the risk of preterm delivery (birth before 37 weeks) or low birth weight.
Why “Category B” Doesn’t Mean Risk-Free
The FDA’s old pregnancy category system (A through X) was a shorthand, not a safety guarantee. Category B simply means animal reproduction studies didn’t find problems, and human studies either haven’t been done or are too small to draw conclusions. Many commonly used medications fall into this category. The key phrase in buspirone’s labeling is that it “should be used during pregnancy only if clearly needed,” which is the FDA’s standard language when data gaps exist.
No reports have linked buspirone to a specific pattern of birth defects, growth restriction, or miscarriage. But the absence of evidence isn’t the same as evidence of absence, particularly with a drug that hasn’t been tracked in large pregnancy registries the way SSRIs have been over the past two decades.
Late Pregnancy and Newborn Effects
Some psychiatric medications taken in the third trimester can cause temporary adjustment problems in newborns, sometimes called neonatal adaptation syndrome. Symptoms can include jitteriness, feeding difficulty, or irritability in the first few days of life. For buspirone specifically, no studies have examined whether this is a concern. That means the risk isn’t documented, but it also hasn’t been ruled out.
The Risk of Leaving Anxiety Untreated
Any conversation about medication safety in pregnancy has to weigh the other side of the equation: what happens if anxiety goes untreated. A large study examining pregnancy outcomes found that untreated anxiety was linked to a significantly higher chance of cesarean delivery (about 1.7 times the usual rate), labor induction (about twice the rate), and longer hospital stays. The effects weren’t limited to the mother. Infants born to women with untreated anxiety had nearly four times the risk of very low Apgar scores at five minutes and roughly three times the risk of oxygen deprivation at birth.
When both anxiety and depression went untreated together, the picture was worse: the risk of postpartum hemorrhage was about 2.5 times higher, and the risk of a serious brain condition in newborns (encephalopathy) increased dramatically. Notably, many of these elevated risks were not seen in women whose anxiety was being treated with medication, suggesting that treatment itself may be protective.
This doesn’t automatically mean medication is the right choice for every pregnant person with anxiety. But it reframes the decision. The comparison isn’t “buspirone versus nothing.” It’s “the uncertain risks of buspirone versus the documented risks of severe, untreated anxiety.”
How Buspirone Compares to SSRIs
SSRIs like sertraline are the most commonly prescribed medications for anxiety during pregnancy, and they have a much larger evidence base. Decades of registry data cover tens of thousands of SSRI-exposed pregnancies. That volume of data allows researchers to identify even small risks with more confidence.
SSRIs are not without concerns of their own. One study found that SSRI use in the second half of pregnancy was associated with roughly four times the risk of a rare but serious newborn lung condition called persistent pulmonary hypertension. Buspirone was grouped with “other antidepressants” in that study, and that broader category showed no statistically significant increase in the same risk. However, buspirone’s numbers in that analysis were too small to draw independent conclusions.
The practical takeaway is that SSRIs have more safety data available, which makes it easier for clinicians to counsel patients about specific risks. Buspirone’s smaller evidence base makes the conversation less precise, not necessarily more dangerous.
Safety During Breastfeeding
If you’re also thinking ahead to postpartum, the breastfeeding data for buspirone is more reassuring. A study measuring buspirone levels in breast milk found the drug was undetectable in all samples, even at doses up to 30 mg twice daily. An active breakdown product of the drug did appear at low levels, but the estimated infant exposure ranged from 0.21% to 2.17% of the mother’s dose. That falls well below the 10% threshold commonly used to flag potential concern. No adverse effects were reported in any of the breastfed infants in the study.
Making the Decision
If you’re currently taking buspirone and have just found out you’re pregnant, don’t stop the medication abruptly on your own. Sudden discontinuation of any anxiety medication can trigger rebound symptoms that may be worse than the original anxiety. The safest approach is to have a conversation with your prescriber as soon as possible so you can weigh your options together, factoring in how severe your anxiety is, whether you’ve tried other approaches, and how far along your pregnancy is.
For some people, the answer will be continuing buspirone because the benefit clearly outweighs the theoretical risk. For others, it may mean switching to a medication with a larger pregnancy safety database, or trying non-medication strategies like cognitive behavioral therapy, which has strong evidence for generalized anxiety and carries no pharmacological risk. The right answer depends on your specific clinical situation, not on a blanket yes or no.