Introduction:
Despite well-justified demands for research to be more inclusive and equitable, pregnancy-specific prescribing information is still greatly lacking for many drugs as pregnant women have been, and remain, consistently underrepresented in clinical research [1,2]. Unfortunately, safety of drugs in pregnancy cannot be reliably inferred from animal studies, or studies in non-pregnant patients [3]. This knowlege gap leaves physicians unaware, and unable to inform their patients, on potential risks or benefits certain medications will have on the patients or their fetuses if used during pregnancy [1]. In the absence of formal clinical trials in pregnancy, alternative data sources need to be explored to provide accurate pregnancy-specific information, such as administrative databases or pregnant patient cohorts. [4,5].
A particular condition for which there is a dearth of pregnancy drug safety information is post-traumatic stress disorder (PTSD), even though this disorder is prevalent in young people who may get pregnant [6]. Prazosin, an antihypertensive medication, has recently gained popularity in the management of post-traumatic stress disorder (PTSD) symptoms, particularly vivid nightmares and sleep-related disorders [7]. Unfortunately, the use of Prazosin in pregnancy is understudied. One recent systematic review identified one clinical trial and five cohort studies to date, [8] but no data on first trimester exposures. Prazosin is a well-tolerated generically available medication, but the lack of pregnancy safety data, especially with regards to first trimester exposures, leaves physicians and health care providers with very limited options on how to counsel and monitor pregnant patients taking this medication [5,9].
Objective: The main objective of this study was to evaluate fetal and pregnancy outcomes in a sample of pregnant patients exposed to Prazosin during the first trimester of pregnancy.
Methods :
This prospective observational study included a sample of patients exposed to Prazosin during their pregnancy. The data comes from the FRAME database of patients who were followed at the Fetal Risk Assessment from Maternal Exposures (FRAME) clinic at London Health Sciences Center, London Ontario between January 1, 2000 to December 31, 2021. The FRAME clinic implements a program in which pregnant women exposed to medications are offered counselling on risks associated with those exposures and followed, when required, by clinical pharmacologists. Patients are asked to consent to participate in the FRAME database, which collects information on the medications they are exposed to, the outcomes of their pregnancies, and documents any effects of their medications on their pregnancies or babies. For this study, the FRAME database was explored to see which patients were taking Prazosin during pregnancy and, for these, additional data were collected from retrospective chart review and by telephone interview. For the telephone interview, initial contact was made by a FRAME physician. Subjects were informed that they could end the telephone interview at any time and that the information provided would be included in the FRAME database for use in potential studies in the future. A total of 20 women who were taking Prazosin and had attended the FRAME clinic were initially identified. Of these, 11 became pregnant while taking the medication, and these formed the final study sample. Data collected included pregnancy and fetal outcomes, if available, such as: miscarriage, preterm birth, preeclampsia, hemorrhage, cesarian section, obtained through electronic chart records and overall pregnancy satisfaction, obtained through phone-call interviews. To assess fetal growth, birth weight was recorded. Data analyses were descriptive (means and frequencies) due to the small sample size. Birthweight corrected for gestational age was assessed and compared to the Canadian normal population distributions, as published by Kramer et al [10] for male and female singletons. The subject’s data was stored as per institutional guidelines. This study was approved by the Western Research Ethics Board (Registration # IRB 00000940).