Stage 1 hypertension linked to higher risk of adverse pregnancy outcomes

Stage 1 hypertension, based on the revised American Heart Association guidelines, exerts adverse effects on pregnancy outcomes, especially in women with prepregnancy normal weight, as suggested in a recent study.

The study involved 47,874 women with singleton live births and blood pressure (BP) <140/90 mm Hg, among whom 5,781 had stage 1a hypertension (systolic BP, 130–134 mm Hg; diastolic BP, 80–84 mm Hg; or both) and 3,267 had stage 1b (systolic BP, 135–139 mm Hg; diastolic BP, 85–90 mm Hg; or both).

Compared with those with normal BP levels, women with stage 1 hypertension were slightly older, more likely to be overweight/obese, and have fasting blood glucose ≥5.1 mmol/L and triglyceride >90th percentile.

More importantly, women with stage 1a and stage 1b hypertension had higher rates of hypertensive disorders in pregnancy (17.5 percent and 22.6 percent vs 7.5 percent), gestational diabetes mellitus (16.7 percent and 18.3 percent vs 11.1 percent), preterm deliveries (4.7 percent and 4.9 percent vs 3.8 percent) and low birth weight <2,500 g (3.2 percent and 3.9 percent vs 2.6 percent) compared with normotensive women.

In multivariable logistic regression models, stage 1a and 1b hypertension were associated with increased risk of hypertensive disorders in pregnancy (adjusted odds ratios [aORs], 2.34 and 3.05, respectively). This association was observed in women with normal weight (body mass index [BMI], 18.5–24.9 kg/m²; aORs, 2.44 and 3.26, respectively) and those who were overweight/obese (BMI, ≥25 kg/m²; aORs, 1.90 and 2.36, respectively).

The current findings suggest a significantly increased adverse pregnancy outcomes associated with stage 1 hypertension in different BMI categories, highlighting a potentially imperative, yet previously unrecognized, need for recognition and management of stage 1 hypertension in early pregnancy.