The association between spontaneous preterm birth and maternal hypertension in the fifth decade of life: a retrospective case–control study

Objective: To investigate whether a history of spontaneous preterm birth (SPTB) predisposes to maternal hypertension. Design: Retrospective case–control study. Setting: Two affiliated university medical hospitals in Amsterdam, the Netherlands. Population: We included 350 women with a history of SPTB between 22 and 36+6 weeks and 166 women with a history of a term birth. Women with pregnancy complications that are known to be associated with cardiovascular disease were excluded. Methods: Both groups underwent cardiovascular risk assessment 9–16 years after pregnancy. We performed a subgroup analysis based upon the severity of SPTB. Main Outcome Measures: Hypertension. Secondary outcomes – metabolic syndrome, mean blood pressure, anthropometrics, blood and urine sampling, Framingham Risk Score and Systematic Coronary Risk Evaluation. Results: A history of SPTB was significantly associated with hypertension; adjusted odds ratio 1.60 (95% confidence interval 1.04–2.46, p = 0.033). Abdominal obesity was more often diagnosed after SPTB (n = 163, 46.6% versus n = 54, 32.5%, p = 0.003) and was more pronounced with more severe preterm birth (p = 0.002). Conclusions: The presence of hypertension 9–16 years after pregnancy was statistically significantly higher among women with a history of SPTB than among women with a history of uncomplicated term birth. Women with a history of SPTB were more often diagnosed with abdominal obesity, especially those with a history of extreme preterm birth.