Abstract
OBJECTIVE: To estimate whether weight gain between deliveries is associated with an increased risk of hypertensive disorders in a subsequent pregnancy. METHODS: This is a case-control study of women who had two live singleton births of at least 24 weeks of gestation at a single maternity hospital from January 1, 2005, to December 31, 2015, with no hypertensive disorder documented in the index pregnancy. Maternal weight gain between deliveries was measured as the change in body mass index (BMI) at delivery. Women who were diagnosed with any hypertensive disorder in the subsequent pregnancy were compared with those who experienced no hypertensive disorder in the subsequent pregnancy using χ statistics for categorical variables and t tests for continuous variables. Logistic regression was used to determine whether weight gain remained independently associated with hypertensive disorders after adjusting for potential confounders. RESULTS: Of 1,033 women, 188 (18.2%) were diagnosed with a hypertensive disorder in the subsequent pregnancy. Of these, 166 (88.3%) had a hypertensive disorder specific to pregnancy (gestational hypertension; preeclampsia; superimposed preeclampsia; or hemolysis, elevated liver enzymes, and low platelet count syndrome), and 22 (11.7%) had chronic hypertension only. Greater weight gain between deliveries was significantly associated with a higher frequency of hypertensive disorders, which remained significant for a BMI increase of at least 2 kg/m in multivariable analyses (adjusted odds ratio [OR] 1.76, 95% CI 1.14-2.74 for 2 to less than 4 kg/m, adjusted OR 3.19, 95% CI 1.86-5.47 for 4 kg/m or more). Conversely, weight loss of 2 kg/m or more was associated with a decreased risk of a hypertensive disorder (adjusted OR 0.41, 95% CI 0.21-0.81). CONCLUSION: Among women with no hypertensive disorder noted in an index pregnancy, an increase in BMI of at least 2 kg/m between deliveries was independently associated with an increased risk of a hypertensive disorder in a subsequent pregnancy.