Saliva as an alternative non-invasive biomarker for the estimation of uric acid levels during pregnancy: A longitudinal study

BACKGROUND: Pregnancy is a physiological condition in which the maternal environment undergoes many changes. Serum uric acid (UA) levels have been used for the early diagnosis of preeclampsia, predictor of reduced birth weight and fetal outcome. UA is also expressed in saliva, and collection of saliva sample is a noninvasive method which will be more acceptable by the patients. AIMS AND OBJECTIVES: The present study aimed to estimate and compare serum and salivary UA levels in age-matched healthy nonpregnant and healthy pregnant women at different trimesters longitudinally. METHODOLOGY: Forty female participants with age ranging between 20 and 38 years comprised the study population. The study group consisted of 20 healthy nonpregnant women (controls) and an equal number of confirmed cases of healthy pregnant women in the first trimester (cases). The cases were followed in their second and third trimesters for the sample collection. RESULTS: Both serum and salivary UA levels were significantly reduced in the first trimester of pregnancy than the controls. In the second and third trimesters, the values of serum and salivary UA levels gradually increased and gained values similar to that of nonpregnant women. Salivary UA levels showed a highly significant positive correlation with serum levels in both controls and cases. CONCLUSION: Salivary estimation, being a noninvasive procedure, is easily accepted by the patients and carries minimal risk of exposure to the blood-borne pathogens compared to serum estimation. Our findings warrant the use of saliva instead of blood for UA estimation.