Objective: In this study, we aim to assess the relationship between laboratory results and pregnancy outcomes of the asymptomatic preripartum women who have been diagnosed incidentally by universal COVID-19 screening upon admission for delivery. Methods: This is a case-control study conducted between January 2021 and March 2022. The study group consisted of the peripartum women with positive PCR result for SARS CoV-2 without the COVID-19 symptoms. Age and gestational age-matched peripartum women were included as the control group (1:3). The primary outcomes measures are inflammatory laboratory parameters (lymphocyte, neuthrophyl, eosinophyl, aspartate aminotransferase, alanin aminotransferase, lactate dehydrognase, neuthrophyl lymphocyte ratio, platelet lymphocte ratio, eosinophyl lymphocyte ratio, monocyte eosinophyl ratio) and their association with a positive PCR result for SARS CoV-2. Additional outcome measures were the associations between asymptomatic COVID-19 and pregnancy, maternal and neonatal outcomes. Results: A total of 369 (95 in study, 274 in control group) women were analyzed. The ROC curve and multivariate logistic regression analysis have shown that increased monocyte-to-eosinophile ratio (MER, ≥14.7, aOR: 3.49 (95% CI 1.893-6.435)) and lactate dehydrogenase (LDH≥214 U/L, aOR: 15.869 (95% CI 8.529-29.524)) levels; and decreased lymphocyte count (≤1.7 103/mm3, aOR:1.8 (95% CI1.27-3.437)) were associated with COVID-19 in asymptomatic peripartum woman. Asymptomatic COVID-19 was associated with an increase in late preterm delivery (p<0.001). Conclusion: Asymptomatic COVID-19 do not cause an increase in maternal and neonatal mortality and major morbidity in peripartum women. Increased monocyte-to-eosinophile ratio (MER, ≥14.7) and LDH (≥214) levels; and decreased lymphocyte count (≤1.7) are associated with COVID-19 in asymptomatic peripartum woman. [ABSTRACT FROM AUTHOR]