title: Association between vitamin D deficiency and primary cesarean section.
abstract: BACKGROUND
  At the turn of the 20th century, women commonly died in childbirth due to rachitic pelvis. Although rickets virtually disappeared with the discovery of the hormone vitamin D, recent reports suggest vitamin D deficiency is widespread in industrialized nations. Poor muscular performance is an established symptom of vitamin D deficiency. The current U.S. cesarean birth rate is at an all-time high of 30.2%. We analyzed the relationship between maternal serum 25-hydroxyvitamin D [25(OH)D] status, and prevalence of primary cesarean section.
  
  
  METHODS
  Between 2005 and 2007, we measured maternal and infant serum 25(OH)D at birth and abstracted demographic and medical data from the maternal medical record at an urban teaching hospital (Boston, MA) with 2500 births per year. We enrolled 253 women, of whom 43 (17%) had a primary cesarean.
  
  
  RESULTS
  There was an inverse association with having a cesarean section and serum 25(OH)D levels. We found that 28% of women with serum 25(OH)D less than 37.5 nmol/liter had a cesarean section, compared with only 14% of women with 25(OH)D 37.5nmol/liter or greater (P = 0.012). In multivariable logistic regression analysis controlling for race, age, education level, insurance status, and alcohol use, women with 25(OH)D less than 37.5 nmol/liter were almost 4 times as likely to have a cesarean than women with 25(OH)D 37.5 nmol/liter or greater (adjusted odds ratio 3.84; 95% confidence interval 1.71 to 8.62).
  
  
  CONCLUSIONS
  Vitamin D deficiency was associated with increased odds of primary cesarean section.
authors.affiliation: Department of Pediatrics, Division of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, and Division of General Pediatrics, Boston Medical Center, Boston, Massachusetts 02118, USA.
authors.forename: Anne
authors.initials: A
authors.lastname: Merewood
authors.forename: Supriya D
authors.initials: SD
authors.lastname: Mehta
authors.forename: Tai C
authors.initials: TC
authors.lastname: Chen
authors.forename: Howard
authors.initials: H
authors.lastname: Bauchner
authors.forename: Michael F
authors.initials: MF
authors.lastname: Holick
mesh_terms: D000328:Adult; D002118:Calcium / Q000097:blood; D002585:Cesarean Section / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D011247:Pregnancy; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium