[Association between elective cesarean section and infants' developmental behaviors: a cohort study].

To investigate the effect of elective cesarean section (ECS) on infants' developmental behaviors. A total of 3 474 pregnant women living in Ma'anshan more than 6 months and accepting obstetric examination in Ma'anshan Maternal and Child Care Center were recruited from May 2013 to September 2014. Excluding participants with pregnancy termination (162), twin pregnancy (39), assisted delivery (14), emergency cesarean section (76) and unclear delivery mode (141), 3 042 pair of mother and infant entered the final analysis. Information of maternal basic demographic characteristics, pregnancy histories, pregnancy life style and pregnancy-related diseases were collected by using self-complied . Information of infants' general condition and delivery modes were acquired from obstetric record. The Ages and Stages Questionnaires-third edition was used to assess infants' communication, gross motor, fine motor, problem solving and person-social function, which was completed at age of 6 months old and 18 months old, respectively. And multi-factor non-conditional logistic regression model was used to analyze the association between ECS and infants' developmental behaviors. The prevalence of ECS was 47.5% (1 443/3 042), among which ECS without medical indication and ECS with medical indication were 27.2% (826/3 042) and 20.3% (617/3 042), respectively. After maternal demographic characteristics, pregnant exposure and infants' basic information adjusted, compared to women with vaginal delivery, both ECS with medical indication and without medical indication increased the risk of a delay in gross motor on infants at 6 months old ( (95 1.72 (1.08-2.77) and 1.87 (1.11-3.15), respectively.) ECS without indication decreased the risk of a delay in fine motor on infants at 6 months old ( (95):0.48 (0.28-0.82)), both ECS without medical indication and with medical indication had no statistically significant effect on 18 months infants' communication, gross motor, fine motor, problem solving and person-social function, the (95) for ECS without medical indication were 0.86 (0.43-1.74), 1.55 (0.86-2.78), 0.74 (0.49-1.15), 1.10 (0.68-1.78) and 1.17 (0.66-2.08), respectively; and the (95) for ECS with medical indication were 0.33 (0.12-1.02), 1.10 (0.55-2.21), 0.79 (0.48-1.29), 0.58 (0.29-1.13) and 1.48 (0.78-2.81), respectively. ECS affected motor development in infants at the age of 6 months old, and no influence was found in infants at the age of 18 months old.