Study populations were selected from among 23,665 deliveries between 1999 and 2003 by a review of the medical charts. Of these, 385 patients who met the criteria of presence of an antenatal record and diagnosis of hypertensive disorder were selected. One hundred and ninety-eight patients were classified as having received little or no prenatal care from an independent, heterogeneous, and traditional physician-based care group, and 187 control women were classified as belonging to the tertiary hospital-based, homogeneous type of prenatal care group.