Delivery Blood Pressure and Other First Pregnancy Risk Factors in Relation to Hypertensive Disorders in Second Pregnancies

Abstract

Background: First pregnancy characteristics and blood pressure (BP) measures may be associated with second pregnancy hypertensive disorder risk. We examined the association between first pregnancy risk factors and second pregnancy hypertensive disorders. Methods: Electronic medical records of nulliparas (n = 26,787) delivering at least twice in Utah (2002-2010) were used. Polychotomous logistic regression models estimated the association of first pregnancy risk factors with second pregnancy hypertensive disorders (gestational hypertension, preeclampsia, or chronic hypertension) stratified by first pregnancy hypertensive status and adjusted for second characteristics. Results: Among normotensive women in their first pregnancy, preterm birth (<34 weeks) and elevated BP at delivery admission in the first pregnancy increased odds of all incident hypertensive disorders in the second. Even borderline admission BP (either systolic or diastolic BP: 130-139 or 85-89mm Hg, respectively) was associated with a doubling of hypertensive disorder risk in a subsequent pregnancy. First pregnancy BP was also associated with recurrence risks for hypertensive disorders, but the relation was stronger for women with gestational hypertension in their first pregnancy with more than 2-fold elevated risk across all BP categories (odds ratios range: 2.32-12.6). However, the majority of women (75%) with a hypertensive disorder in the first pregnancy do not repeat this outcome in the second pregnancy. Conclusion: Delivery admission BP of a first pregnancy was strongly related to hypertensive disorder incidence and recurrence in the subsequent pregnancy. Although crude, these measures may prove useful as a predictor of long-term maternal health and future pregnancy risk.