Kate Bramham clinical research fellow, Bethany Parnell medical student, Catherine Nelson-Piercy professor of obstetric medicine, Paul T Seed senior lecturer in medical statistics, Lucilla Poston professor of Women’s Health, Lucy C Chappell clinical senior lecturer in maternal and fetal medicine et al
Bramham K, Parnell B, Nelson-Piercy C, Seed P T, Poston L, Chappell L C et al.
Chronic hypertension and pregnancy outcomes: systematic review and meta-analysis
BMJ 2014; 348 :g2301
doi:10.1136/bmj.g2301
Re: Chronic hypertension and pregnancy outcomes: systematic review and meta-analysis
The research article concludes that women with chronic hypertension in US studies have an approximately threefold increased risk of delivery before 37 weeks’ gestation, birth weight <2500 g, and neonatal intensive care admission and a fourfold increased risk of perinatal death compared with the US general pregnancy population1. This systematic review and meta-analysis also shows that women with chronic hypertension have a high pooled incidence of superimposed pre-eclampsia and all other pregnancy complications1
Compared with the US general pregnancy population, the incidence of superimposed pre-eclampsia on average across study populations was nearly eightfold higher compared with pre-eclampsia1.
But my concern is that preterm delivery, caesarean sections, low birth weights, neonatal intensive care admissions and perinatal deaths are all complications of pre-ecclampsia alone. And as said above, that in chronic hypertension there is a high incidence of superimposed pre-eclampsia. So we may infer that the lion's share of complications due to chronic hypertension may be due to superimposed pre-eclampsia. In that case, patients with chronic hypertension with super-imposed pre-eclampsia need more attention in the antenatal period. This factor has to be studied in isolation as the meta-analysis has not answered this.
Competing interests: No competing interests