Multivariate analysis of risk factors, including parity, maternal age, FH of hypertension, high pre-pregnancy BMI, and NOS3 GA+AA genotype, revealed that the AGT TT genotype, a positive FH of hypertension, and advanced maternal age were strong independent risk factors for severe PIH among the subgroup with the PAI-1 4G/4G genotype; the estimated ORs and their 95% CIs were 2.75 (1.22–6.17), 2.48 (1.10–5.56), and 2.87 (1.26–6.54), respectively. This evidence concerns the gene SERPINE1 and Hypertension.