September 10th, 2012
Antihypertensive Use Among Pregnant Women on the Rise
Growing numbers of pregnant women are taking antihypertensive drugs that may harm themselves or their babies, according to a new study published in Hypertension.
Brian Bateman and colleagues analyzed Medicaid data on more than 1.1 million pregnant women from 2000 to 2007. Overall, 4.4% of the women received antihypertensive medications at some point during their pregnancy. During the study period, the use of antihypertensive drugs increased from 3.5% to 4.9%. This increase, according to the authors, is “consistent with the rising rates of chronic hypertension and gestational hypertension… which in turn may reflect rising rates of obesity and advanced maternal age in US parturients.”
Exposure to antihypertensive drugs occurred in 1.9% of women during the first trimester, 1.7% during the second trimester, and 3.2% during the third trimester. ACE inhibitors, which are contraindicated in late pregnancy, were used by 4.9% of antihypertensive users in the second trimester and 1.1% in the third. The authors said that automatic refills and the “prescribing physicians’ failure to ask about the possibility of pregnancy are two plausible explanations.”
About one half to two thirds of women who had been taking antihypertensive drugs prior to their pregnancy discontinued treatment during the first or second trimester. According to the authors, although antihypertensive therapy for mild-to-moderate hypertension can prevent progression to severe hypertension, it is unknown whether it can reduce the risk for pregnancy complications, including placental abruption, fetal demise, superimposed preeclampsia, preterm birth, or maternal morbidity.
“While we know high blood pressure, or hypertension, occurs in about 6 percent to 8 percent of all pregnancies, we know little about how women and their doctors treat the condition,” said Bateman, in an AHA press release.
The authors pointed out that “there is virtually no data on the comparative effectiveness and safety of the different treatment options for hypertension” in pregnant women. They concluded: “Research investigating the comparative safety and efficacy of antihypertensive therapy in pregnancy is urgently needed to define the optimal approach to therapy.”