The association of maternal serum uric acid with the risk of small for gestational age newborn: a retrospective cohort study

Problem: Prior results on the association between serum uric acid (UA) levels in the early trimester and the risk of small for gestational age (SGA) remain unclear. This study evaluated the association of maternal first-, second-, and third-trimester UA levels with the risk of SGA infants.Method of study: A total of 23, 194 singleton mothers from the International Peace Maternity and Child Health Hospital between January 2014 and January 2017 were included. Maternal UA levels were measured at 12.1 +/- 1.08th (UA1) and 32.2 +/- 1.03th (UA2) gestational weeks. Delta UA was calculated as the difference between UA2 and UA1. Logistic regression and restricted cubic spline (RCS) were performed to evaluate the association between maternal UA and Delta UA during pregnancy and SGA. Receiver operating characteristic (ROC) analysis was employed to assess the serum uric acid prediction value.Results: Women in the higher quartiles of UA1 had a significantly higher risk of SGA. A clear increased risk for SGA was observed with higher quartiles for UA2 (p for trend <0.05). An approximately "J-shaped" relationship was observed between UA2 and Delta UA, and the risk of SGA was observed. When compared with those with a lower level of UA in the first trimester, those with a higher level of UA1, the more increase in the later UA levels were associated with a higher risk of SGA [adjusted odds ratio (aOR) = 1.67, 95% CI:1.37-2.05]. The ROC curve areas were 0.525 for UA1, 0.582 for UA2 and 0.576 for Delta UA.Conclusions: The findings suggested that non-preeclamptic and non-hypertensive women who experienced early pregnancy with high UA levels had an elevated risk of SGA. Moreover, a high maternal UA level in the earlier trimester may be an early predictor of SGA.