After the studies, researchers have said that pregnant women with chronic hypertension (high blood pressure) are highly likely to suffer from adverse pregnancy outcomes such as preterm delivery, low birth weight and neonatal death.
Almost 1-5 per cent of pregnancies, chronic hypertension cause complication. The problem may be increasing because of changes in the antenatal population.
Researchers from King's College London, combined data from studies from 55 studies done in 25 countries to to assess the strength of evidence linking chronic hypertension with poor pregnancy outcomes.
The researchers looked at the following outcomes: preterm delivery (delivery before 37 weeks' gestation); low birth weight (below 2500g); perinatal death (fetal death after 20 weeks' gestation including stillbirth and neonatal death up to one month) and admission to neonatal intensive care or special care baby units.
To conclude, researchers said that "chronic hypertension is associated with a high incidence of adverse pregnancy outcomes compared with a general population".