Secular Trends in the Rates of Preeclampsia, Eclampsia, and Gestational Hypertension, United States, 1987-2004

The increase in gestational hypertension may be exaggerated because of the revised clinical guidelines published in the 1990s; these same revisions would likely have reduced diagnoses of preeclampsia. Therefore, our observation of a small but consistent increase in preeclampsia is a conservative indication of a true population-level change.