Correlation between serum uric acid levels before delivery and adverse pregnancy outcomes

Currently, many cross-sectional studies have investigated the correlation between prenatal serum uric acid (SUA) levels and adverse pregnancy outcomes; however, studies with larger sample sizes and a more rational approach to confirm this correlation are lacking.

In this cross-sectional study, baseline data and laboratory indicators of pregnant women before delivery were collected from multiple medical centers in Guizhou, China, from January 2010 to December 2020, encompassing data from 116725 women. Trends in adverse fetal outcomes across quartiles of SUA were assessed. A logistic regression analysis was performed to estimate the odds ratios for adverse pregnancy outcomes based on SUA quartiles. Generalized additive models (GAMs) and restricted cubic splines (RCSs) were used to treat SUA as an original continuous variable and to visualize its nonlinear relationship with adverse pregnancy outcomes.

According to the corresponding inclusion criteria, 104645 women were ultimately included. Maternal SUA levels were positively associated with the risk of premature delivery, low birth weight (LBW), very low birth weight (VLBW) and low Apgar scores. Compared with pregnant women in the lowest SUA quartile, those in the highest SUA quartile had a 1.273-fold increased risk of LBW (95% CI: 1.147-1.413) and 1.741-fold increased risk of VLBW (95% CI: 1.311-2.313). Pregnant women with hyperuricemia exhibited higher risks of premature delivery (aOR = 1.084; 95% CI: 1.001-1.173), LBW (aOR = 1.449; 95% CI: 1.317-1.595) and VLBW (aOR = 1.825; 95% CI: 1.369-2.434). Unadjusted generalized additive models revealed a U-shaped association between the SUA level and the probability of LBW and lower Apgar scores. After adjusting for covariates, the GAM and RCS analyses indicated a U-shaped association between the SUA level and the probability of premature delivery, LBW, VLBW and Apgar scores <7.

In Southwest China, high pre-delivery SUA levels are significantly associated with increased risks of premature delivery and low birth weight. Our data reveal a U-shaped association, suggesting that moderate SUA levels are linked to optimal outcomes, whereas extremely low concentrations showed a non-significant risk trend. While this retrospective study cannot establish causality, it underscores the value of SUA monitoring. Prospective studies are warranted to further clarify the clinical significance of low SUA levels.