Strengths and Limitations
Our study has several strengths. First, it was a retrospective cohort study allowing us to evaluate the outcomes of COVID-19 from early pregnancy to follow-up. Second, we have evaluated several parameters during early pregnancy including clinical, laboratory, imaging and placental pathology.
Meanwhile, our study has some limitations. Our study only enrolled five cases with COVID-19. Therefore, our results may not be generalizable for other populations. The number of cases is limited and further studies are needed. Second, foetal and maternal outcomes were only observed until two-months of follow-up, which provides limited information. Further follow-up is important to assess the long-term effects of maternal COVID-19 to the infant.