Related factors of cesarean section and predictive validity based on Robson Ten-Group Classification System / 中华围产医学杂志

ABSTRACT

Objective To explore the relationship between the obstetric factors defined by Robson Ten-Group Classification System (RTGCS) and cesarean section rate (CSR),and to evaluate the validity of predictive models established based on the RTGCS for cesarean section.Methods Clinical data of 41 295 cases delivered in Shanghai First Maternity and Infant Hospital from January 1,2012 to September 30,2014 were retrospectively collected.CSR of different groups categorized by the RTGCS was analyzed by descriptive epidemiological methods by three models.Model 1 was obstetrics factors (parity,history of cesarean section,number of fetus,mode of labor,fetal presentation and gestational age);model 2 was obstetrics factors (model 1) + demographic characteristics and severity (maternal age and with/without treatment in intensive care unit);model 3 was defined as model 2+ complications (placenta previa,placental abruption,chronic or gestational hypertension,preeclampsia,renal disease,or human immunodeficiency virus infection).The relationship between obstetrics factors classified by the RTGCS and CSR was analyzed by the logistic regression model (the potential confounders were controlled).The validity of predictive models was evaluated by analyzing the area under the receiver operative characteristic (ROC) curve.Results (1) There were statistical differences in total CSR and CSR before labor among those cases respectively grouped by age,medical insurance,parity,signal/multiple pregnancy,fetal presentation and gestational age (all P＜0.05).(2) The recruited cases were categorized into ten groups according to the RTGCS and among them,the second group (single,cephalic presentation,nulliparous,≥ 37 gestational weeks,induced labor or cesarean section before labor) accounted for most of the cesarean section cases (61.2％,11 217/18 322),followed by the fourth group (single,cephalic presentation,multiparous,no previous cesarean section,≥ 37 gestational weeks,induced labor or cesarean section before labor),which were 11.2％ (2 061/18 322).(3) Obstetrical parameters,including parity,number of fetus,mode of delivery,history of cesarean section,fetal presentation and gestational weeks at delivery were related to CSR,even after adjustment for maternal age and medical insurance,or obstetrical complications,or both above factors (all P＜0.05).(4) Areas under the ROC curves and the 95％ confidence intervals of model 1,2 and 3 were 0.867 (0.863-0.870),0.875 (0.872-0.878) and 0.881 (0.878-0.885),respectively (all P＜0.01).Conclusion Related variables of RTGCS highly correlate with CSR and could be used as promising indicators for prediction of cesarean section.The RTGCS is of great application value to those research subjects.