Maternal hyperuricemia superimposed on maternal hypertension aggravates the risk of small-for-gestational-age fetus

Small-for-gestational-age (SGA) fetus is an important public health issue because of its high mortality and long-term effects on health. Maternal hyperuricemia is associated with diverse adverse pregnant outcomes and neonatal disturbance. We aimed to evaluate whether maternal hyper-uric acid (HUA) is associated with the risk of SGA fetus and to explore whether it can modify the association between maternal hyper-blood pressure (HBP) and SGA fetus.

We performed a population-based cross-section retrospective study, a total of 6715 pregnant females were recruited. Multiple logistic regression analysis was performed to identify risk factors significantly correlated with SGA fetus, and then studied the effect of maternal HUA on the association between maternal HBP and SGA fetus.

We collected 537 SGA fetuses among 6715 pregnant females. Maternal HUA was an independent risk factor for SGA delivery (odds ratio (OR), 2.737; 95% confidence interval (CI), 2.110-3.551). A dose-response association between maternal uric acid and SGA delivery was found among normotensive and hypertensive group. Compared with those whose uric acid was lower than 270 μmo/L with normal-blood pressure (NBP), the risk for SGA delivery in those whose uric acid was higher than 370 μmo/L with stage 2 or 3 hypertension increased 12.695-fold.

Our results suggest that maternal HUA could increase the risk of neonatal SGA, and maternal HUA could be superimposed upon pre-existing maternal HBP and increase the risk for SGA fetus.