title: Risk factors for retained placenta in southwestern Nigeria.
abstract: BACKGROUND
  This study aimed to determine the incidence of, and identify independent risk factors to retained placenta in Ile-Ife, southwestern Nigeria.
  
  
  METHODS
  This was a prospective case-control study involving 120 women with retained placenta after vaginal birth at the Obafemi Awolowo University Teaching Hospital, Ile-Ife, southwestern Nigeria over a period of seven years. Two consecutive normal deliveries after each retained placenta served as controls. Following a bivariate analysis, a multivariate logistic regression model was constructed in order to define independent risk factors for retained placenta while controlling for confounding variables.
  
  
  RESULTS
  During the study period, there were 120 cases of retained placenta, and the total number of deliveries was 6,160, making the incidence 1.9 percent. Independent risk factors associated with retained placenta include non-use of antenatal care (odds-ratio [OR] 22.71, 95 percent confidence interval [CI] 10.5-49.12, p-value is less than 0.000), previous retained placenta (OR 15.22, 95 percent CI 3.30-70.19, p-value is less than 0.000), previous caesarean section (OR 12.00, 95 percent CI 2.05-70.19, p-value is less than 0.006), maternal age 35 years or more (OR 7.10, 95 percent CI 1.5-32.40, p-values is less than 0.012), grand multiparity (OR 6.63, 95 percent CI 1.88-23.40, p-value is less than 0.003), previous dilatation and curettage (OR 4.44, 95 percent CI 1.69-11.63, p-value is less than 0.002), preterm delivery (OR 3.12, 95 percent CI 1.12-8.68, p-value is less than 0.029) and placenta weight less than 501 g (OR 2.91, 95 percent CI 1.34-6.32, p-value is less than 0.007).
  
  
  CONCLUSIONS
  Women with identifiable risk factors should be targeted for the prevention of retained placenta. There is a need for the training of birth attendants in the proper conduct of delivery and third stage of labour to prevent placenta retention and postpartum haemorrhage.
authors.affiliation: Department of Obstetrics, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Osun 220005, Nigeria. alexandrerowolabi@yahoo.com
authors.forename: A T
authors.initials: AT
authors.lastname: Owolabi
authors.forename: F O
authors.initials: FO
authors.lastname: Dare
authors.forename: O B
authors.initials: OB
authors.lastname: Fasubaa
authors.forename: I O
authors.initials: IO
authors.lastname: Ogunlola
authors.forename: O
authors.initials: O
authors.lastname: Kuti
authors.forename: L A
authors.initials: LA
authors.lastname: Bisiriyu
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002585:Cesarean Section; D005260:Female; D006801:Humans; D009549:Nigeria; D010298:Parity; D010920:Placenta; D018457:Placenta, Retained / Q000175:diagnosis* / Q000453:epidemiology; D011247:Pregnancy; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors