Evaluation of US State-Level Variation in Hypertensive Disorders of Pregnancy

Abstract

Importance: Hypertensive disorders of pregnancy are important causes of maternal and perinatal morbidity in the US. However, the extent of statewide variation in the prevalence of chronic hypertension, pregnancy-induced hypertension or preeclampsia, and eclampsia in the US remains unknown.

Objective: To examine the extent of statewide variation in the prevalence of chronic hypertension, hypertensive disorders of pregnancy (including pregnancy-induced hypertension or preeclampsia), and eclampsia in the US.

Design, setting, and participants: A cross-sectional study using 2017 US birth certificate data was conducted from September 1, 2019, to February 1, 2020. A population-based sample of 3 659 553 women with a live birth delivery was included.

Main outcomes and measures: State-specific prevalence of chronic hypertension, hypertensive disorders of pregnancy, and eclampsia was assessed using multilevel multivariable logistic regression, with the median odds ratio (MOR) to evaluate statewide variation.

Results: Of the 3 659 553 women, 185 932 women (5.1%) were younger than 20 years, 727 573 women (19.9%) were aged between 20 and 24 years, 1 069 647 women (29.2%) were aged between 25 and 29 years, 1 037 307 women (28.3%) were aged between 30 and 34 years, 523 607 women (14.3%) were aged between 35 and 39 years, and 115 487 women (3.2%) were 40 years or older. Most women had Medicaid (42.8%) or private insurance (49.4%). Hawaii had the lowest adjusted prevalence of chronic hypertension (1.0%; 95% CI, 0.9%-1.2%), and Alaska had the highest (3.4%; 95% CI, 3.0%-3.9%). Massachusetts had the lowest adjusted prevalence of hypertensive disorders of pregnancy (4.3%; 95% CI, 4.1%-4.6%), and Louisiana had the highest (9.3%; 95% CI, 8.9%-9.8%). Delaware had the lowest adjusted prevalence of eclampsia (0.03%; 95% CI, 0.01%-0.09%), and Hawaii had the highest (2.8%; 95% CI, 2.2%-3.4%). The degree of statewide variation was high for eclampsia (MOR, 2.36; 95% CI, 1.88-2.82), indicating that the median odds of eclampsia were 2.4-fold higher if the same woman delivered in a US state with a higher vs lower prevalence of eclampsia. Modest variation between states was observed for chronic hypertension (MOR, 1.27; 95% CI, 1.20-1.33) and hypertensive disorders of pregnancy (MOR, 1.17; 95% CI, 1.13-1.21).

Conclusions and relevance: The findings of this study suggest that after accounting for patient-level and state-level variables, substantial state-level variation exists in the prevalence of eclampsia. These data can inform future public-health inquiries to identify reasons for the eclampsia variability.

Figure 1.. Prevalence of Chronic Hypertension

The circles indicate the mean prevalence. The whisker bars indicate 95% CIs. Dashed horizontal line indicates the overall mean prevalence for all states.

Figure 2.. Prevalence of Hypertensive Disorders of Pregnancy

The circles indicate the mean prevalence. The whisker bars indicate 95% CIs. Dashed horizontal line indicates the overall mean prevalence for all states.

Figure 3.. Prevalence of Eclampsia

The circles indicate the mean prevalence. The whisker bars indicate 95% CIs. Dashed horizontal line indicates the overall mean prevalence for all states. South Carolina and Tennessee did not report eclampsia; therefore, births in these states were excluded from the analytic sample.