Correlation of Serum Uric Acid and Serum Uric Acid/Creatinine Ratio Levels with Adverse Pregnancy Outcomes in Late Pregnancy

Abstract

Background The disorder of serum uric acid metabolism during pregnancy is associated with adverse pregnancy outcomes, while few studies have analyzed and compared the correlation of serum uric acid and serum uric acid/creatinine ratio levels with adverse pregnancy outcomes. Objective To explore the correlation of serum uric acid and serum uric acid/creatinine ratio levels with adverse pregnancy outcomes in late pregnancy. Methods A total of 743 pregnant women with singleton live births who were routinely examined and delivered at Nanjing Drum Tower Hospital from 2015 to 2022 were selected . Based on the occurrence of adverse pregnancy outcomes, pregnant women were divided into normal group (344 cases) and adverse outcome group (399 cases) . Serum uric acid and serum uric acid/creatinine ratio were divided into three levels by quartiles, respectively, including Q1 (serum uric acid<257 μmol/L) , Q2 (serum uric acid 257-359 μmol/L) , Q3 (serum uric acid>359 μmol/L) and q1 (serum uric acid/creatinine ratio<5.88) , q2 (serum uric acid/creatinine ratio 5.88-7.94) , q3 (serum uric acid/creatinine ratio>7.94) . According to the median age of pregnant women, they were divided into the age subgroup<30 years old (341 cases) and age subgroup≥ 30 years old (402 cases) . Based on previous pregnancies and deliveries, they were divided into the primiparous subgroup (539 cases) and multiparous subgroup (194 cases) . The correlation of serum uric acid and serum uric acid/creatinine ratio levels with adverse pregnancy outcomes was analyzed by using multivariate Logistic regression. Results Pregnant women in adverse outcomes group were older with higher levels of BMI, serum uric acid, serum uric acid/creatinine ratio and triglycerides than those in the normal group (P<0.05) . After adjustment for confounders, the multivariate Logistic regression results of the effect of serum uric acid and serum uric acid/creatinine ratio on adverse pregnancy outcomes showed that, compared to Q1 serum uric acid level, the risk of preeclampsia (AOR=4.41, 95%CI=2.16-8.99) and intrauterine growth restriction (AOR=3.59, 95%CI=1.08-11.96) increased at Q3 serum uric acid level (P<0.05) ; compared to q1 serum uric acid/creatinine ratio level, the risk of preeclampsia (AOR=2.33, 95%CI=1.13-4.79; AOR=3.56, 95%CI=1.68-7.56) increased at q2 and q3 serum uric acid/creatinine ratio levels. Compared to q1 serum uric acid/creatinine ratio level, the risk of preterm labor (AOR=2.76, 95%CI=1.33-5.71) and intrauterine growth restriction (AOR=5.15, 95%CI=1.39-19.14) increased, while the risk of macrosomia (AOR=0.43, 95%CI=0.19-0.98) and large for gestational age (AOR=0.38, 95%CI=0.15-0.96) decreased (P<0.05) . The results of the effect of serum uric acid and serum uric acid/creatinine ratio on preeclampsia and preterm labor in different age subgroups showed that, compared to Q1 serum uric acid level, the risk of preeclampsia increased in both age subgroups at Q3 serum uric acid level (P<0.05) ; compared to q1 serum uric acid/creatinine ratio level, the risk of preeclampsia increased among women aged≥30 years at q2 and q3 serum uric acid/creatinine ratio level (P<0.05) . The results of the effect of serum uric acid and serum uric acid/creatinine ratio on preeclampsia and preterm labor in different pregnancies and deliveries subgroups showed that compared to Q1 serum uric acid level, the risk of preeclampsia increased at Q3 serum uric acid level among primiparous women (P<0.05) ; compared to q1 serum uric acid/creatinine ratio level, the risk of preeclampsia increased at q2 and q3 serum uric acid/creatinine ratio level among primiparous women, as well as the risk of preterm birth at q3 serum uric acid/creatinine ratio level among primiparous women (P<0.05) . Conclusion Elevated levels of serum uric acid and serum uric acid/creatinine ratio were associated with the risk of preeclampsia and intrauterine growth restriction, in which preeclampsia mainly occurred in pregnant women aged≥30 years or primiparous women. The risk of preterm labor was increased at high levels of serum uric acid/creatinine ratio, primarily in primiparous women. Serum uric acid/creatinine ratio predicted more adverse pregnancy outcomes than serum uric acid.

Keywords

• pregnant women|pregnancy outcome|uric acid|uric acid/creatinine ratio|adverse outcomes|root cause analysis