Strengths and limitations
Our study has several strengths. First, two cities provided a similar sample size. Wuhan as the epidemic center was included. Further, to reduce selection bias, questionnaires were distributed to multi-centers mainly through the nationwide online data platform (YunYiTong). As a result, the representativeness of our participants, for pregnant women in Wuhan and Chongqing, is reliable.
Our study sample is relatively good for pregnant women in other places (especially in emerging epidemic areas around the world). However, appropriate adjustments need to be made before the relevant application. In the comparative results, Chongqing, as a municipality adjacent to Hubei Province (Wuhan is the provincial capital city), is significantly affected than other regions far away from Wuhan, which may weaken the impact gap of COVID-19. Descriptive results were observed cross-region and are likely to be found in other places.
Some limitations should also be considered when interpreting the results. Firstly, the study design suggests the possibility of self-report bias. Secondly, the anxiety level may be underestimated. Pregnant women who are not registered on the Internet platform or not registered in the hospital may not participate, and they may have a lower socio-economic status and a higher level of anxiety.32 In addition, pregnant women in the middle and late stages of their pregnancy accounted for the majority of the subjects, and the highest level of anxiety reported in the past should be early pregnancy.32 Finally, this is a cross-sectional study, so long-term studies such as post-traumatic stress disorder or postpartum mental state are worth following up.