RESUMO
OBJECTIVES: To compare the distribution of uric acid (UA) concentration in women with normal and preeclamptic pregnancy, to investigate the significance of UA concentration in diagnosis of preeclampsia, and to estimate the UA rate of change over time before delivery. STUDY DESIGN: A case-control study of singleton pregnancies was completed at a tertiary care center in Kingston, Ontario. Patients with preeclampsia were recruited through two prospective cohort studies (n = 218); the Preeclampsia New Emerging Team (September 2003-October 2009) and the Maternal Health Clinic (May 2011-June 2016). Individuals who had an uncomplicated pregnancy and delivered (July 2016-August 2017), were included in the control arm (n = 73). MAIN OUTCOME MEASURES: Longitudinal analysis using a linear mixed-effects model examined the UA rate of change over time. The distribution of the UA level was compared using a t-test. The significance of the UA level in the diagnosis of preeclampsia was examined using multiple logistic regression. RESULTS: The rate of change in UA before delivery had an increasing non-constant logarithmic trend with time. Mean UA level in preeclamptic pregnancies (369.53 ± 75.78 µmol/l) was significantly elevated compared with the normal pregnancies (292.55 ± 54.73 µmol/l). UA had an adjusted odds ratio of 1.39 (95%CI: 1.14-1.69; P = 0.001) associated with the incidence of preeclampsia and UA level >349 µmol/l close to delivery is an accurate measurement for diagnosing preeclampsia. CONCLUSION: The UA concentration in preeclamptic pregnancies is significantly increased compared to normal pregnancies and the level of UA may have diagnostic ability in the occurrence of preeclampsia.
