title: [Estimate of HIV-1 infection prevalence in pregnant women and effectiveness of zidovudine administered during pregnancy in the prevention of vertical transmission].
abstract: BACKGROUND
  Despite the proven efficacy of zidovudine (ZDV) for reducing perinatal transmission of HIV-1, questions remain about its implementation and effectiveness in routine practice. The aims of this study were to assess the impact of ZDV administered during pregnancy in preventing perinatal HIV-1 transmission, and to determine the proportion of early identification of maternal HIV-1 infection over time.
  
  
  METHODS
  We prospectively followed from birth a cohort of children born between 1/1/1987 and 31/10/1997 to HIV-1-infected mothers. Infant infection status was assessed by follow-up beyond 18 months or HIV-PCR up to 3 months of age.
  
  
  RESULTS
  229 mothers and 248 infants were identified in the cohort. ZDV was administered during pregnancy as monotherapy to 34 mothers for a mean of 4.7 (3.1) months prior to delivery. There were no differences in baseline characteristics between the treated and untreated groups. Mean (SD) CD4 cell count was 465 (261) cells x 10(6)/l. Factors associated with transmission were a more prolonged time of rupture of obstetric membranes (median 6 vs 1.04 hours; p = 0.023) and ZDV treatment. Among the ZDV-treated mothers only one child was infected (2.9%), whereas 37 children born to 212 untreated women became infected. (OR: 0.14; 95% CI: 0.07-0.92). The estimated prevalence of HIV-1 in pregnant women in our area is about 0.39% (95% CI: 0.34-0.45). From 1987 to 1991, 9.7% of infected women were nor identified at the perinatal period, as compared to 2.5% in the last 5 years of the study period (p = 0.034).
  
  
  CONCLUSIONS
  In this study, the estimated prevalence of HIV-1 infection is high. ZDV during pregnancy is significantly associated with a decrease in perinatal transmission in our setting. The awareness of an effective treatment might have contributed to the increased identification of HIV-infected mothers prior to delivery observed over time in our cohort of children born to HIV-infected mothers.
authors.affiliation: Unidad de Inmunodeficiencias, Hospital 12 de Octubre, Madrid.
authors.forename: J T
authors.initials: JT
authors.lastname: Ramos Amador
authors.forename: J R
authors.initials: JR
authors.lastname: Contreras
authors.forename: R
authors.initials: R
authors.lastname: Bastero
authors.forename: C
authors.initials: C
authors.lastname: Barrio
authors.forename: P
authors.initials: P
authors.lastname: Moreno
authors.forename: R
authors.initials: R
authors.lastname: Delgado
authors.forename: E
authors.initials: E
authors.lastname: Muñoz
authors.forename: J
authors.initials: J
authors.lastname: Jiménez
mesh_terms: D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission*; D015497:HIV-1; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D008297:Male; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy* / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D015215:Zidovudine / Q000627:therapeutic use*
chemical_list: D019380:Anti-HIV Agents; D015215:Zidovudine