Outcome measures
The definitions of PE and GH were those of the International Society for the Study of Hypertension in Pregnancy.15 In GH, the diastolic blood pressure should be 90 mm Hg or more on at least two occasions 4 h apart developing after 20 weeks of gestation in previously normotensive women in the absence of significant proteinuria and in PE there should be GH with proteinuria of 300 mg or more in 24 h or two readings of at least ++ on dipstick analysis of midstream or catheter urine specimens if no 24-h collection is available. In PE superimposed on chronic hypertension significant proteinuria (as defined above) should develop after 20 weeks of gestation in women with known chronic hypertension (history of hypertension before conception or the presence of hypertension at the booking visit before 20 weeks of gestation in the absence of trophoblastic disease).
The obstetric records of all women with preexisting or pregnancy-associated hypertension were examined to determine whether the condition was chronic hypertension, PE or GH. Similarly, for quality control, we examined the records of 500 randomly selected cases without pregnancy-associated hypertension.