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).