We prospectively examined 9149 singleton pregnancies between March 2006 and November 2007. We excluded 783 (8.6%) because they had missing outcome data (n=443), there was a major fetal defect or aneuploidy (n=153), the pregnancies resulted in fetal death or miscarriage before 24 weeks of gestation (n=139), the pregnancies were terminated for social reasons (n=15), or when there was at least one episode of hypertension but on the basis of the available data it was not possible to determine whether the diagnosis was PE (n=33). In the remaining 8366 cases, there were 165 (2.0%) that developed PE including 37 that required delivery before 34 weeks (early-PE) and 128 with late-PE, 140 with GH and 8061 (96.4%) cases that were unaffected by PE or GH.