The Association of Familial Hypertension and Risk of Gestational Hypertension and Preeclampsia.

It has not been established how history of hypertension in the father or mother of pregnant women, combined with obesity or smoking, affects the risk of main forms of pregnancy-induced hypertension. A cohort of 912 pregnant women, recruited in the first trimester, was assessed; 113 (12.4%) women developed gestational hypertension (GH), 24 (2.6%) developed preeclampsia (PE) and 775 women remained normotensive (a control group). Multiple logistic regression was used to calculate adjusted odds ratios (AOR) (and 95% confidence intervals) of GH and PE for chronic hypertension in the father or mother of pregnant women. Some differences were discovered. (1) Paternal hypertension (vs. absence of hypertension in the family) was an independent risk factor for GH (AOR-a = 1.98 (1.2-3.28), = 0.008). This odds ratio increased in pregnant women who smoked in the first trimester (AOR-a = 4.71 (1.01-21.96); = 0.048) or smoked before pregnancy (AOR-a = 3.15 (1.16-8.54); = 0.024), or had pre-pregnancy overweight (AOR-a = 2.67 (1.02-7.02); = 0.046). (2) Maternal hypertension (vs. absence of hypertension in the family) was an independent risk factor for preeclampsia (PE) (AOR-a = 3.26 (1.3-8.16); = 0.012). This odds ratio increased in the obese women (AOR-a = 6.51 (1.05-40.25); = 0.044) and (paradoxically) in women who had never smoked (AOR-a = 5.31 (1.91-14.8); = 0.001). Conclusions: Chronic hypertension in the father or mother affected the risk of preeclampsia and gestational hypertension in different ways. Modifiable factors (overweight/obesity and smoking) may exacerbate the relationships in question, however, paradoxically, beneficial effects of smoking for preeclampsia risk are also possible. Importantly, paternal and maternal hypertension were not independent risk factors for GH/PE in a subgroup of women with normal body mass index (BMI).