[Construction and evaluation of weight retention nomogram prediction model for women 1 year after delivery]

To analyze the influencing factors of body weight retention in woman at 1 year postpartum, and to construct and evaluate a nomogram prediction model for postpartum 1-year weight retention.

From September 2010 to February 2011, 468 pregnant women in the third trimester were recruited from Yuexiu District and Baiyun District Maternal and Child Health Hospital in Guangzhou, and followed up to 1 year postpartum. The basic demographic information of pregnant women was collected by self-made questionnaire. Dietary intake in the third trimester was investigated by 3-day 24-hour dietary review. The weight of women before delivery and one year after delivery were measured. According to whether the weight retention at 1 year postpartum is greater than 0 kg, the study subjects were divided into the 1-year postpartum weight retention group and weight recovery group. Logistic regression analysis were used to screen the influencing factors of weight retention at 1 year postpartum. R 4.2.3 software was used to construct the nomogram prediction model. The subject working characteristic curve, calibration curve, Hosmer-Lemeshow goodness of fit test and clinical decision curve were used to evaluate the model's differentiation, accuracy and clinical applicability.

Among 329 subjects in the model training set, the 1-year postpartum weight retention was 68.09%, and the median and quartile levels of retained body weight were 5.0(3.0, 10.0)kg. After Logistic analysis, a nomogram prediction model was constructed based on five factors: pre-pregnancy body mass index(BMI), pregnancy weight gain, parity, gravitity, 0-6 months postpartum feeding pattern. The model had good discrimination(AUC_(training)=0.778, AUC_(testing)=0.767) and accuracy(Hosmer-Lemeshow test: P_(training)=0.946, P_(testing)=0.891).

The 1-year postnatal weight retention nomogram model based on women's pre-pregnancy BMI, pregnancy weight gain, parity, gravitity, 0-6 months postpartum feeding pattern has good differentiation, accuracy and clinical applicability.