(A22) Utilization of antihypertensives before, during, and after pregnancy

Publication Number: 305

Background: Hypertension among women of childbearing age is increasing. Adequate blood pressure control during pregnancy is necessary to prevent maternal and neonatal morbidity and mortality, but many antihypertensives are teratogens, complicating risk-benefit decisions.

Objectives: To examine the utilization patterns of different classes of antihypertensives among women with hypertension before, during, and after pregnancy.

Methods: We used MarketScan® Commercial Claims and Encounters databases to analyze antihypertension utilization among pregnancy episodes with conception between 2010 to 2018. We included pregnancies among individuals aged 12 to 55 years that resulted in both live and non-live births. Pregnancy outcomes and start/end dates were identified using a validated algorithm. We required continuous health plan enrollment from 180 days before conception until 180 days after pregnancy end date. Hypertension was identified as ≥1 inpatient or ≥2 outpatient encounters for hypertension in the 6 months before conception. Antihypertensive utilization was defined as ≥1 outpatient pharmacy claim during target periods: 4-6 months (4-6M) and 0-3 months (0-3M) before pregnancy, 1st/2nd/3rd trimester (T1/2/3), 0-3M and 4-6M after pregnancy.

Results: We identified 20,874 pregnancy episodes among women with hypertension (T2: 14,134; T3: 13,169). About 65.1% (16,484) used antihypertensives during the 0-6M before pregnancy, and 21.5% (3,544 out of 16,484) discontinued during pregnancy. Overall utilization during pregnancy was 59.0%, 55.1%, and 56.8% in each trimester. β-blockers were the most frequently used antihypertensives before (4-6M: 27.6%; 0-3M: 30.2%), during (T1: 30.8%, T2: 31.8%, T3: 33.8%), and after (0-3M: 35.5%; 4-6M: 28.3%) pregnancy. The use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and thiazide diuretics during 4-6M before pregnancy was 14.9%, 7.9%, and 23.0%, respectively. These decreased during pregnancy (T1: 7.1%, 4.5%, and 12.8%), especially during later trimesters (T3: 1.9%, 1.5%, and 3.6%). Calcium channel blocker use during pregnancy remained stable at around 13%. Use of methyldopa was higher during pregnancy (T1: 14.7%, T2: 15.4%, T3: 15.2%) compared to utilization before (4-6M: 7.1%; 0-3M: 9.0%) and after (0-3M: 9.7%; 4-6M: 6.8%) pregnancy. Users with >1 antihypertensive class ranged from 42% before/after pregnancy to 20% - 34% during pregnancy.

Conclusions: Overall utilization of antihypertensives decreased during pregnancy, with changing prevalence of different classes of antihypertensives. Research evaluating the choice of antihypertensives and optimal timing to switch to safer alternatives considering maternal and fetal outcomes is warranted.