Objective: To examine the relationship between interpregnancy interval (IPI) after previous cesarean section (CS) and perinatal outcomes. Design: Retrospective cohort study. Setting: West China Second University Hospital, Sichuan University, China. Population: A total of 1854 women with a history of CS who delivered from January 2016 to December 2016. Methods: With an IPI of 24-59 months as the reference, the associations between various IPIs (<24, 60-119, and ≥120 months) and perinatal outcomes were examined by multivariate logistic regression analysis with multiple models. Main outcome measures: Adverse maternal and fetal outcomes of different IPIs after CS. Results: IPI <24 months significantly increased the risk of anemia in late pregnancy (aOR 2.09, 95% CI 1.21-2.62, p = 0.008). IPI <24 months was associated with a higher risk for incomplete uterine rupture (OR 1.30, 95% CI 1.05-1.61), IPI ≥60 months was related to a lower risk for incomplete uterine rupture (IPI = 60-119 months: OR 0.77, 95% CI 0.62-0.95; IPI ≥120 months, OR 0.59, 95% CI 0.38-1.08), and women with IPI ≥120 months were more likely to develop gestational hypertension (GHP) (p = 0.036) and gestational diabetes mellitus (GDM) (p = 0.001). These effects became nonsignificant after adjusting possible confounders. Conclusion: IPI <24 months is associated with a higher risk for anemia in late pregnancy. IPI may combine with other factors to affect GHP, GDM, and uterine rupture in the subsequent pregnancy after previous CS. Funding: National Natural Science Foundation of China (No. 81571465). Keywords: Adverse pregnancy outcomes, Birth spacing, Cesarean delivery.

Background: COVID-19 outbreak in Wuhan, China recently. It quickly spread throughout. Objectives: To investigate clinical features and outcomes of pregnant women with COVID-19. Search Strategy: PubMed、Web of Science、EMBASE、MEDLINE were searched from January 1, 2020 to April 16, 2020. Selection Criteria: Case review of pregnant women infected with COVID-19 Data Collection and Analysis: Two reviewers screened 366 literatures and 14 studies included, four reviewers independently extracted the features of the literatures. We used random-effects model to analyze incidence (P) and 95% confidence interval (95%CI). Heterogeneity was assessed using the I2 statistic. Main Results: The meta- analysis included 236 pregnant women with COVID-19. The results were as follows: positive CT findings (71%; 95%CI, 0.49~0.93), cesarean section (65%; 95%CI, 0.42~0.87), fever (51%; 95%CI, 0.35~0.67), lymphopenia (49%; 95%CI, 0.29~0.70), coexisting disorders (33%; 95%CI, 0.21~0.44), cough (31%; 95%CI, 0.23~0.39), fetal distress (29%; 95%CI, 0.08~0.49), preterm labor (23%; 95%CI, 0.14~0.32), severe case or death (12%; 95%CI, 0.03~0.20). The subgroup analysis showed compared with nonpregnant patients, pregnant women with COVID-19 had significantly lower incidences of fever (pregnant women group, 51%; nonpregnant patients group, 91%; P＜0.00001) and cough (pregnant women group, 31%; nonpregnant patients group, 67%; P＜0.0001). Conclusions: The incidence of fever, cough and positive CT findings in pregnant women with COVID-19 is less than that in the general population, preterm labor is the opposite. There is no evidence that COVID-19 can propagate vertically for the time being. Keywords: 2019-nCoV, COVID-19, clinical features, pregnancy outcomes, pregnant women, meta-analysis