title: Cesarean delivery on maternal request and childhood intelligence: a cohort study.
abstract: BACKGROUND
  Cesarean section births have been steadily increasing over the past decade and have become an epidemic in China. Cesarean delivery on maternal request is a major contributor to this upward trend, and there has been of much concern about its impact on maternal and child health. Most of mothers believe that cesarean delivery on maternal request can improve the child's intelligence, but direct evidence is sparse. In this cohort study, we aimed to directly assess the impact of cesarean delivery on maternal request on childhood intelligence.
  
  
  METHODS
  Intelligence quotient (IQ) of 4144 preschool children from 21 cities/counties of Zhejiang and Jiangsu province whose mothers were registered in a population-based perinatal surveillance program during 1993-1996 was assessed with Chinese Wechsler Young Children Scale of Intelligence (C-WYCSI) in 2000. The outcomes were full-scale IQ, verbal IQ, and performance IQ of C-WYCSI. Mode of delivery and covariates were obtained from the surveillance program. We estimated unadjusted and adjusted effects of cesarean delivery on maternal request and assisted vaginal delivery on IQ scores compared with spontaneous vaginal delivery using regression analysis.
  
  
  RESULTS
  The mean full-scale, verbal, and performance IQ for all children was 99.3 ± 16.1, 93.6 ± 17.7, and 105.3 ± 14.3. In crude analysis, cesarean delivery on maternal request versus spontaneous vaginal delivery was associated with an increase of 3.9 (95% confidence interval, 0.6 to 7.2) points in full-scale IQ, 4.8 (1.2 to 8.4) points in verbal IQ, and 2.4 (-0.6 to 5.3) points in performance IQ. After adjusting for maternal education, occupation, and IQ, the advantage was reduced to 1.6 (-1.3 to 4.5), 2.3 (-0.8 to 5.5), and 0.6 (-2.0 to 3.3) points for full-scale, verbal, and performance IQ, respectively. Assisted vaginal delivery versus spontaneous vaginal delivery was not associated with IQ scores in any analysis.
  
  
  CONCLUSIONS
  Neither cesarean delivery on maternal request nor assisted vaginal delivery affected children's IQ.
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijng 100191, China.
authors.forename: Hong-Tian
authors.initials: HT
authors.lastname: Li
authors.forename: Rong-Wei
authors.initials: RW
authors.lastname: Ye
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Pei
authors.forename: Ai-Guo
authors.initials: AG
authors.lastname: Ren
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Zheng
authors.forename: Jian-Meng
authors.initials: JM
authors.lastname: Liu
mesh_terms: D002585:Cesarean Section / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D007361:Intelligence Tests; D008297:Male; D011247:Pregnancy