Table 3 presents the unadjusted ORs for the association between each risk factor and PIH for the entire population. The risk of PIH increased with each BMI category and became
significant starting with a BMI in the overweight range (OR 1.99, 95% CI 1.73-2.31) and increased to the greatest odds among women with a BMI of _40 kg=m2 (OR 4.26, 95% CI
3.37-5.38). Also significant was a diagnosis of chronic hypertension, the presence of prepregnancy diabetes, a diagnosis of gestational diabetes, and weight gain of _40 lb. Race was a significant factor, with black women at greatest risk compared to white women, but Hispanic and Asian women were at diminished risk. Nulliparity also conferred a higher risk for PIH, whereas tobacco use did not. Insurance type was not associated with an increased odds of PIH; however, being unmarried was associated with a small increase (OR 1.23 95%
CI 1.10-1.39) compared with being married. Table 4 shows the unadjusted and adjusted ORs for women without chronic hypertension for whom nulliparity, prepregnancy diabetes, race=ethnicity, and BMI _25 remained significant predictors of PIH. Unlike the results for the overall population, the association between PIH and gestational diabetes was no longer significant among this group of women without hypertension. In addition, the increased risk associated with black race was no longer significant. As shown in Table 4, the adjusted ORs for women without chronic hypertension were generally similar to unadjusted ORs. Nulliparity, Hispanic ethnicity, Asian or American Indian race, and maternal prepregnancy BMI remained significant predictors