Demographic factors that can be used to predict early-onset pre-eclampsia

Objective: To define the maternal demographic factors that predicts the risk of developing early-onset pre-eclampsia (requiring delivery before 34 weeks' gestation) in an Australian population. These are compared to risk factors described in a British population to determine whether the Fetal Medicine Foundation (FMF) risk algorithm for predicting early-onset pre-eclampsia needs to be modified for an Australian population.

Methods: A secondary analysis of prospective cohorts in Australia and in the United Kingdom was conducted. Demographic details and past medical history were obtained. Odds ratios (ORs) for the development of early-onset pre-eclampsia were calculated for maternal factors in both populations. Forest plots were used to compare the two sets of odds ratios.

Results: In the Australian population, pre-existing hypertension (OR 19.89, 95% CI 4.17-94.93) and body mass index >40 kg/m(2) (OR 9.04, 95% CI 1.13-72.40) predicted risk of developing early-onset pre-eclampsia. There were no significant differences in the odds ratios for maternal factors in the two populations.

Conclusions: This study shows that the ORs used to describe risks associated with maternal characteristics in the FMF algorithm for early-onset pre-eclampsia are consistent with those found in our local population. There does not appear to be any value in changing the weighting of demographic factors included in the FMF algorithm for an Australian population.