title: [Trends in perinatal HIV transmission and possible related factors].
abstract: BACKGROUND
  Since the introduction of zidovudine, perinatal transmission (PT) of HIV-1 has markedly decreased, although a transmission rate of zero has still not been achieved. The present study describes the trend in PT over 13 years, as well as changes in medical-surgical management and their influence on PT.
  
  
  METHODS
  We performed a prospective cohort study of all HIV-1-infected mother-infant pairs born between January 1987 and December 1999 in Hospital 12 Octubre in Madrid. Univariate analysis was performed to determine the relationship between possible risk factors and PT.
  
  
  RESULTS
  A total of 290 mothers and 291 children were included. Thirty-eight children were infected, 28 of these before 1994 (PT rate: 13 %). There were no cases of infection when the full ACTG 076 protocol was implemented. Factors significantly associated with a higher transmission rate were prolonged rupture of membranes and nonelective caesarean section. The main protective factor was antiretroviral therapy.
  
  
  CONCLUSIONS
  PT markedly decreased after the introduction of the ACTG 076 protocol. In the last 13 years, maternal age and maternal infection due to heterosexual transmission have increased. Other changes observed were modifications in obstetric interventions and the generalized use of zidovudine and antiretroviral therapy during pregnancy.
authors.affiliation: Servicio de Inmunodeficiencias, Hospital 12 de Octubre, Madrid, Spain. jmedina@hcas.sespa.es
authors.forename: María I
authors.initials: MI
authors.lastname: González Tomé
authors.forename: J T
authors.initials: JT
authors.lastname: Ramos Amador
authors.forename: S
authors.initials: S
authors.lastname: Guillén Martín
authors.forename: E
authors.initials: E
authors.lastname: Muñoz Gallego
authors.forename: J
authors.initials: J
authors.lastname: Sánchez Granados
authors.forename: I
authors.initials: I
authors.lastname: Solís Villamarzo
authors.forename: J
authors.initials: J
authors.lastname: Ruiz Contreras
mesh_terms: D000328:Adult; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000635:transmission*; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000706:statistics & numerical data*; D008297:Male; D011446:Prospective Studies