Antimigraine drugs may complicate pregnancy

The antimigraine medications dihydroergotamine (DHE) and triptan seem to aggravate the risk of adverse pregnancy outcomes such as premature birth and spontaneous abortion (SA), a recent study has found.

For the analysis of low birthweight, prematurity, and major congenital malformations (MCM), the researchers assessed 233,900 singleton pregnancies. Meanwhile, 317,040 pregnancies were assessed for SA. Cases were retrieved from the Quebec Pregnancy Cohort. Drug exposures were obtained from prescription fillings and validated by comparing against maternal reports.

A total of 15,688 (6.7 percent) pregnant women had premature delivery, mostly between 32 and 36 weeks of gestation. DHE use during pregnancy significantly increased the risk of prematurity (adjusted risk ratio [RR], 4.12, 95 percent confidence interval [CI], 1.21–13.99). Triptan exposure had no such effect.

MCMs were detected in 24,539 newborns, and this outcome correlated with higher maternal age, maternal migraine, smoking, and comorbidities such as hypertension and diabetes. While neither antimigraine medication increased the overall risk of MCMs, triptan use did aggravate the likelihood of gastrointestinal defects (adjusted RR, 2.04, 95 percent CI, 1.01–4.11).

Triptans also worsened the risk of SA (adjusted odds ratio, 1.63, 95 percent CI, 1.34–1.98), of which 29,104 cases were reported. DHE use doubled the risk estimate for SA but failed to reach significance.

“We have shown that our results are unlikely due to indication bias or unmeasured confounders. It remains, however, that further confirmation in a larger cohort is warranted,” the researchers said.