Kate Bramham, MBBS, from King’s College London, and colleagues conducted a systematic review and meta-analysis to investigate complications of pregnancy in women with chronic hypertension. A total of 55 studies were identified, which included 795,221 pregnancies. The incidence of each pregnancy outcome was pooled, and for US studies, the pooled incidence was compared with the US general population incidence.
The researchers found that there were high pooled incidences of complications of pregnancy for women with chronic hypertension, including superimposed preeclampsia (25.9%, cesarean section (41.4%), preterm delivery before 37 weeks’ gestation (28.1%), birth weight below 2,500g (16.9%), admission to the neonatal unit (20.5%), and perinatal death (4.0%). Considerable heterogeneity was observed for the reported incidence of all outcomes. No influential demographic factors were identified in additional meta-regression. On comparison of the incidences of adverse outcomes for women with chronic hypertension from US studies with women from the US national population dataset, the risks of pregnancy outcomes were increased for women with chronic hypertension (relative risks: superimposed preeclampsia compared with preeclampsia, 7.7; cesarean section, 1.3; preterm delivery before 37 weeks, 2.7; birth weight below 2,500g, 2.7; neonatal unit admission, 3.2; and perinatal death, 4.2).
“These findings should inform counseling and contribute to optimization of maternal health, drug treatment, and pre-pregnancy management in women affected by chronic hypertension,” the authors write.