Baseline Measures
At baseline, participant demographic characteristics and pregnancy-related data, such as age, education, height, prepregnancy weight, number of pregnancies, and prior abortions, were collected through a self-designed electronic questionnaire (by scanning a QR code on the smartphone) before randomization. In addition, delivery information, including gestational age of delivery, birth mode, perineal injury, and neonatal weight, was obtained by checking the electronic medical record system after delivery.All outcomes were measured at baseline, 2 months after randomization, and 6 weeks post partum. The control group completed follow-up assessments electronically (via a QR code linked to questionnaires), whereas the experimental group completed the questionnaires provided in the Online Evaluation forum of the UIW app.