First Trimester Uric Acid and Adverse Pregnancy Outcomes

BACKGROUND The association of elevated serum uric acid with the development of hypertension is established outside of pregnancy. We investigated whether first trimester uric acid was associated with the development of the following: gestational hypertension or pre-eclampsia, these outcomes stratified by presence of hyperuricemia at delivery since this denotes more severe disease, preterm birth, or small for gestational age (SGA). METHODS Uric acid was measured in 1,541 banked maternal plasma samples from a prior prospective cohort study that were collected at a mean gestational age of 9.0 (+/- 2.5) weeks. Polytomous regressions were performed and adjusted for parity and prepregnancy body mass index (BMI). RESULTS First trimester uric acid in the highest quartile (> 3.56 mg/dl) compared to lowest three quartiles was associated with an increased risk of developing pre-eclampsia (adjusted odds ratio (OR) = 1.82; 95% confidence interval (CI), 1.03-3.21) but not gestational hypertension. In women with hypertensive disease complicated by hyperuricemia at delivery, high first trimester uric acid was associated with a 3.22-fold increased risk of hyperuricemic gestational hypertension (HU) and a 3.65-fold increased risk of hyperuricemic pre-eclampsia (HPU). High first trimester uric acid was not associated with gestational hypertension or pre-eclampsia without hyperuricemia (H or HP) at delivery, preterm birth, or SGA. In women who developed hypertensive disease, elevated uric acid at delivery was only partly explained by elevated uric acid in the first trimester (r(2) = 0.23). CONCLUSIONS First trimester elevated uric acid was associated with later pre-eclampsia and more strongly with pre-eclampsia and gestational hypertension with hyperuricemia.