Abstract: Background：The prevalence of hyperuricemia (HUA) is increasing, which is not only related to gout, urate nephropathy and kidney stones, but also related to the occurrence and development of endocrine metabolism, cardiovascular and cerebrovascular diseases. Objective：To assess the association of maternal hyperuricemia with adverse pregnancy outcomes and neonatal disease. Design：Retrospective nested casecontrol study. Methods：Data were retrospectively collected from People's Hospital of Peking University between January 1st 2020 and December 31st 2020. According to the maternal uric acid value in the third trimester of pregnancy, the newborns were divided into the group of HUA and normal uric acid. The pregnancy outcomes and clinical outcomes of neonates in two groups were compared. According to the maternal uric acid value in the third trimester of pregnancy(μmol·L-1), pregnant women were divided into the group of low concentration (<360), medium concentration (~420) and high concentration (>420). Linear regression and logistic regression models were used to analyze the relationship between maternal uric acid value and preterm, low birth weight and smallforgestationalage infants. Spearman rank correlation analysis was used to analyze the correlation between maternal uric acid value in the third trimester of pregnancy and neonatal uric acid value at 24 hours after birth. Main outcome measures：The relationship between maternal uric acid value and preterm and low birth weight and smallforgestationalage infants. Results：A total of 2 397 pregnant women (2 581 newborns) were enrolled, of which 216 cases (9%) were in the HUA group. The birth weight of newborns in the HUA group was lower than that of the nonHUA group (2 925 g vs 3 260 g, P<0.001). The proportions of preterm birth (18.5% vs 8.9%), low birth weight (23.1% vs 7.1%), small for gestational age (29.2% vs 10.6%), and transfer to pediatrics (19.9% vs 11.1%) were higher in the HUA group (P<0.001). The birth weight of newborns in the high concentration group was lower than those in the low concentration group (-54g，95%CI: -106.48-1.63, P=0.043). The risk of newborns with preterm and smallforgestationalage infants delivery increased by 74% (OR=1.74，95%CI:1.082.8, P=0.023) and 85% (OR=1.85，95%CI：1.262.73，P=0.002), respectively. The uric acid value of the newborn at 24 hours after birth was moderately correlated with the uric acid value of the pregnant mother in the third trimester of pregnancy (r=0.613, P=0.000). There was no significant difference in neonatal complications between the two groups. Conclusion：Maternal hyperuricemia in the third trimester of pregnancy is associated with the occurrence of perterm, low birth weight and smallforgestationalage infants.

Key words: The third trimester of pregnancy, Hyperuricemia, Low birth weight, preterm, Small for gestational age infant