Lower systolic blood pressure levels in early pregnancy are associated with a decreased risk of early-onset superimposed preeclampsia in women with chronic hypertension: a multicenter retrospective study.

To clarify the impact of blood pressure (BP) management ranges on pregnancy outcomes, we conducted a multicenter retrospective analysis of 215 women with singleton pregnancies diagnosed with essential hypertension either before or within 14 weeks of gestation. Patients were classified according to systolic BP (sBP; <130, 130-139, 140-159, and ≥160 mmHg) or diastolic BP (dBP; <80, 80-89, 90-109, and ≥110 mmHg) at 8-11, 12-15, and 16-19 weeks of gestation. The risk of early-onset superimposed preeclampsia and small-for-gestational-age neonates was assessed in each BP group. Moreover, a subgroup analysis was performed in 144 eligible patients whose BP was measured at both 12-13 and 14-15 weeks of gestation. At 16-19 weeks of gestation, higher sBP significantly increased the incidence of early-onset superimposed preeclampsia (13.3%, 24.6%, 32.2% and 75.0%, respectively) and small-for-gestational-age neonates (6.0%, 13.1%, 16.9% and 50.0%, respectively). Multivariate logistic regression analyses showed that women with sBP < 130 mmHg at 16-19 weeks of gestation had a significantly lower risk of early-onset superimposed preeclampsia than women with sBP of 140-159 mmHg. Subgroup analyses also showed that even at 14-15 weeks of gestation, sBP < 130 mmHg was associated with a significantly lower risk of early-onset superimposed preeclampsia than an sBP of 140-159 mmHg. In conclusion, sBP < 130 mmHg within 14 weeks of gestation reduced the risk of developing early-onset superimposed preeclampsia in women with chronic hypertension.