Background: Since its announcement as a pandemic, COVID-19 has been shown to be associated with more severe outcomes among pregnant women. Infected mothers may develop Intrauterine Growth Retardation (IUGR), stillbirth, premature labor, and Disseminated Intravascular Coagulation when carrying a child (DIC). The present study aimed to estimate the risk of severe COVID-19 and its correlation with adverse neonatal outcomes among pregnant women. Methods: This was a population-based, retrospective cohort study of all pregnancies with a live birth or fetal death in Mashhad, Iran, from February 20, 2020, to June 21, 2020, on 460 patients who tested positive for COVID-19. The assessed neonatal outcomes included preterm birth, IUGR, stillbirth, severe neonatal asphyxia, and neonatal death. Modified Poisson and multinomial logistic regression models were used to derive relative risk estimates. Results: 460 patients identified with COVID-19 during pregnancy were assessed in the study. Overall, the most prevalent complication was preterm birth, with a total of 119 (25. 9) cases. In multivariable analysis, the risk of preterm labor, low birth weight, severe neonatal asphyxia, ICU-admitted mother, the length of hospitalization> 7 days and IUGR were significantly increased in the Stillbirth. The risk of global preterm birth had also significantly increased in the Stillbirth group compared to the other group (91. 7% versus 23. 7%, aOR = 3. 66, 95% CI [8. 85-165. 87], p < 0. 001). Conclusion: Along with the possibility of more severe COVID-19 infection among pregnant women, five complicated outcomes were described in the present study, including preterm birth, IUGR, stillbirth, severe neonatal asphyxia, and neonatal deaths as risk factors of COVID-19 infection in pregnancy.