Increased incidence of hypertensive disorders of pregnancy in women with a history of spontaneous preterm birth: A longitudinal linked national cohort study

Objective: Determine the risk of hypertensive disorders of pregnancy (HD) in women with a history of spontaneous preterm birth (SPTB). Study design: Longitudinal linked national cohort study within the Dutch Perinatal Registry (1999–2009) on linked data among 349,291 women with a first and second singleton pregnancy in the Netherlands. Main outcome measures: The incidence of HD, small for gestational age (SGA) and placental abruption in the second pregnancy. Results: Out of 349,291 women with a singleton first pregnancy, 19,991 (5.7%) had a SPTB. The incidence of HD in the second pregnancy was 8.1% in women with a previous SPTB, as compared to 5.6% in women with a previous term birth (aOR 1.49 (CI 1.41–1.57)). Also after excluding HD, SGA and/or placental abruption in the first pregnancy, women with a history of SPTB had a higher risk of HD in their second pregnancy compared to women with a previous term birth (4.6% versus 2.7%, aOR 1.77 (CI 1.64–191)). Similarly, the incidence of SGA and placental abruption was higher in the second pregnancy in women with a history of SPTB compared to term birth in the first pregnancy. Conclusions: Women with a history of SPTB are at elevated risk of HD in the subsequent pregnancy. These results support shared pathophysiology between SPTB and HD.