History Of Premature Birth Increase Long-term Risk Of Hypertension In Women

Objectives To assess the impact of premature birth(PTB) on the long-term risk of hypertension in women.Methods This was a ambispective cohort study, and a total of 4430 pregnant women who gave birth in Kailuan General Hospital between October 1976 and December 2008 were enrolled. All women were classified into the PTB group(n=248) and the non-PTB group(n=4182) according to their PTB history. The cumulative incidence of hypertension was calculated and multiple COX proportional hazards regression models was adopted to the analysis of the effect of premature birth on hypertension.Results 1 The follow-up time was 2 to 35(15.02±7.62) years. 2 During the follow-up period, compared with non- premature birth group, levels of childbearing age, prenatal systolic and diastolic blood pressures, postpartum systolic and diastolic blood pressures,and the prevalence of pregnancy-induced hypertension were significantly high, while levels of maternal height,fundal height,gestational age, weight and height of newborn babies were significantly low in premature birth group(P<0.05 for all). At an annual checkup between 2006 and 2007, age, systolic and diastolic blood pressures were significantly higher, while proportion of physical exercise lower in premature birth group than in nonpremature birth group(P<0.05 for all). 3 There were 943 hypertension events during the follow-up. The cumulative incidence of hypertension was 25.8%. In premature birth group and, the cumulative incidence of hypertension was 36.4%, while the corresponding cumulative incidence was 25.1% in non-premature birth group(P<0.01). According to the PIH, childbearing age, grouphypertensive family history stratification, in addition to the PIH group, the cumulative incidence of hypertension were significantly higher in premature birth group than in non-premature birth group(P<0.05 for all).Multiple COX proportional hazards models indicated that women with premature birth were 1.87 times(95% confidence interval: 1.05~3.33) more likely to develop hypertension than those without after adjusting for other traditional risk factors.Conclusions Cumulative incidence was higher in women with premature birth than those without, suggesting that premature birth may be an independent long-term risk factor for hypertension...