Author Contribution
Y L: data collect, summarize the data, data analysis, follow-up,
drafting and revised the article. YN L, J Z: obstetrics and gynecology
data analysis. JC L, YC Z, KM L:
data statistics, drawing. XM F, revised the article. JG W: plan the
study, study design, revised the article. All authors critically
reviewed the manuscript, provided important intellectual input, approved
the final version and agreed to be accountable for their contributions.