Many women stop antihypertensive meds during pregnancy
An observational study reveals that many hypertensive women stop taking their antihypertensive medications during pregnancy, although it was unclear whether it was appropriate to do so.
“[This was observed] even [among] women with a severely high BP documented before pregnancy,” said Dr Chen Lu from Kaiser Permanente Washington Health Research Institute in Seattle, Washington, US.
The population-based cohort study involved 5,782 women with chronic hypertension receiving antihypertensive medications within 120 days prior to pregnancy and who later gave birth to a singleton in three Kaiser Permanente regions in the US. Their use of antihypertensive medication was characterized from 120 days prior to pregnancy through delivery. Their highest systolic and diastolic BP (SBP and DBP) within 120 days before pregnancy were also recorded.
While thiazide diuretics (41 percent), beta-blockers (27 percent) and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEIs/ARBs; 24 percent) were the most commonly used drug classes before pregnancy, this pattern switched to labetalol (37 percent) and methyldopa (28 percent) as the predominant medications taken during pregnancy.
During pregnancy, as many as 1,037 (18 percent) of the cohort did not fill their antihypertensive medications, despite many (n=881) having documented at least one severe high BP episode (SBP ≥160 or DBP ≥110 mm Hg) before pregnancy.
In particular, women who were on ACEI/ARBs (23 percent) or thiazides (20 percent) before becoming pregnant were most likely to not fill their medications during pregnancy.
Although some medications are considered to be unsafe during pregnancy, the reasons for stopping or switching antihypertensive medications were unclear from the study, as the participants did not report on the reasons for doing so. It was also impossible to tell from the study whether such behaviour was appropriate or not, Chen pointed out.
“Research is needed to understand impact of these treatment interruptions on pregnancy outcomes and women’s long-term health,” said Chen.
Previous studies have suggested that very high BP during pregnancy can lead to adverse foetal outcomes such as growth restriction, preterm birth, and placental abruption. According to the researchers, patients should discuss with their doctors before making any decision to change or stop their antihypertensive medications.