Prospective evaluation of pregnancy outcomes after gestational exposure to prazosin

Prazosin is an antihypertensive medication which can be used to help with post-traumatic stress disorder (PTSD) symptoms. Little data is currently available on its safety in pregnancy. The aim of this study was to assess the fetal and pregnancy safety associated with prazosin exposures in early pregnancy.

Subjects were 11 patients who took prazosin during pregnancy and were counselled at the FRAME clinic in London Health Sciences Centre (Ontario, Canada) between 1 January 2000 and 31 December 2021. Data on their other exposures and pregnancy outcomes were collected from medical records and through telephone questionnaires.

It was found that 6/11 (54.5%) subjects did not report any adverse outcomes and experienced uneventful pregnancies. There were two miscarriages. Birthweights were within the normal range for the remaining nine pregnancies. Adverse events reported were consistent with background population expectation, including: one postpartum haemorrhage, one case of preeclampsia, one preterm birth, two NICU admissions, and two caesarean sections.

For these 11 subjects, pregnancy outcomes after exposure to prazosin were consistent with typical outcomes from unexposed pregnancies. More data are needed to conclude that prazosin is safe for use in pregnant subjects. However, the lack of adverse effects above baseline is reassuring to future patients who may be unintentionally exposed to prazosin while pregnant. Therefore, this study contributes valuable data towards monitoring safety of prazosin in pregnancy.