Results
558 pregnancies in 467 WWE were retrospectively reviewed in this study. Because 81 pregnancies fulfilled the exclusion criteria of the study, 477 pregnancies in 401 WWE were gathered for final analysis. There were 188 pregnancies (188/477, 39.4%) in the planned-pregnancy group and 289 pregnancies (289/477, 60.6%) in the unplanned-pregnancy group. The flowchart of the study is presented in Figure 1.