Chronic hypertension in pregnancy stratified by first-trimester blood pressure control and adverse perinatal outcomes: A prospective observational study

Risk for adverse maternal outcomes among women with chronic hypertension

OBJECTIVE

To determine whether longitudinal health data accounts for end-organ injury or death in the setting of chronic hypertension.

DESIGN

Cohort of 64 799 deliveries to 61 854 women.

SETTING

US claims data for the preiod 2008-2019.

POPULATION

Women with a delivery hospitalisation and chronic hypertension.

METHODS

Risk for a composite of acute end-organ injury or death during the delivery hospitalisation and 30 days postpartum was analysed. Adjusted logistic regression models were derived with discrimination for each model estimated by the C-statistic. Poisson regression was used to estimate adjusted risk ratios. Starting with models using data from pregnancy, further adjustment was performed accounting for healthcare use in the year prior to pregnancy, including hospitalisations, emergency department encounters, prescription medications and pre-pregnancy diagnoses.

MAIN OUTCOME MEASURES

Acute end-organ injury or death.

RESULTS

The composite outcome occurred among 5.7% of 64 799 deliveries. For patients with commercial insurance, filling non-hypertensive medications from ≥11 different classes, compared with none (adjusted risk ratio, aRR 4.07, 95% CI 2.86-5.79), three or more hospitalisations before pregnancy, compared with none (aRR 4.75, 95% CI 3.46-6.52), and chronic kidney disease diagnosed in the year before pregnancy (aRR 2.35, 95% CI 1.88, 2.94) were associated with increased risk. For pregnancies covered by commercial insurance, the C-statistic increased from 0.615 (95% CI 0.599-0.630) in the model with pregnancy data only to 0.796 (95% CI 0.783-0.808) for the model additionally including healthcare use in the year before pregnancy. Findings with Medicaid were similar.

CONCLUSIONS

Prepregnancy care use predicted adverse maternal outcomes. These data may be important in risk stratification.

A retrospective review of pregnancy outcomes in women with uncomplicated mild to moderate chronic hypertension

OBJECTIVE

To examine pregnancy complications in women with uncomplicated mild-moderate chronic hypertension (CHTN) treated with antihypertensives prior to 20 weeks compared to those not on antihypertensives.

STUDY DESIGN

This retrospective cohort study examined singleton pregnancies of women with mild-moderate CHTN who delivered from 01/2014-3/2019. Pregnancies complicated by hypertension at ≥ 20 weeks, end organ damage, preexisting diabetes mellitus, early-onset gestational diabetes, multifetal gestation, and fetal anomalies were excluded. Adjusted logistic regression analyses were performed for each of the outcomes. Adjusted odds ratios (aOR) were reported along with associated 95% confidence intervals (CI) and p-values.

MAIN OUTCOME MEASURES

Primary outcome was superimposed preeclampsia with severe features. Additional maternal outcomes were superimposed preeclampsia without severe features, severe hypertension, indicated preterm delivery, placental abruption, and mode of delivery. Neonatal outcomes included composite perinatal outcomes (fetal growth restriction, intrauterine fetal demise, and small for gestational age neonate), low birth weight, very low birth weight, admission to the neonatal intensive care unit, and Apgar score <7 at 5-minutes.

RESULTS

345 women were identified: 232 (67.2%) were not taking antihypertensives and 113 (32.8%) were taking ≥1 antihypertensive. There was no significant difference in the primary outcome (p = 0.65; aOR = 0.88; 95% CI 0.51-1.52) among the group taking antihypertensive therapy as compared to those not taking antihypertensives. No statistically significant differences were seen for any of the other secondary maternal or neonatal outcomes.

CONCLUSIONS

Our data supports that the use of antihypertensive therapy in women with mild-moderate CHTN does not reduce the risk of developing superimposed preeclampsia.