title: Characteristics and management of HIV-1-infected pregnant women enrolled in a randomised trial: differences between Europe and the USA.
abstract: BACKGROUND
  Rates of mother-to-child transmission of HIV-1 (MTCT) have historically been lower in European than in American cohort studies, possibly due to differences in population characteristics. The Pediatric AIDS Clinical Trials Group Protocol (PACTG) 316 trial evaluated the effectiveness of the addition of intrapartum/neonatal nevirapine in reducing MTCT in women already receiving antiretroviral prophylaxis. Participation of large numbers of pregnant HIV-infected women from the US and Western Europe enrolling in the same clinical trial provided the opportunity to identify and explore differences in their characteristics and in the use of non-study interventions to reduce MTCT.
  
  
  METHODS
  In this secondary analysis, 1350 women were categorized according to enrollment in centres in the USA (n = 978) or in Europe (n = 372). Factors associated with receipt of highly active antiretroviral therapy and with elective caesarean delivery were identified with logistic regression.
  
  
  RESULTS
  In Europe, women enrolled were more likely to be white and those of black race were mainly born in Sub-Saharan Africa. Women in the US were younger and more likely to have previous pregnancies and miscarriages and a history of sexually transmitted infections. More than 90% of women did not report symptoms of their HIV infection; however, more women from the US had symptoms (8%), compared to women from Europe (4%). Women in the US were less likely to have HIV RNA levels <400 copies/ml at delivery than women enrolling in Europe, and more likely to receive highly active antiretroviral therapy, and to start therapy earlier in pregnancy. The elective caesarean delivery rate in Europe was 61%, significantly higher than that in the US (22%). Overall, 1.48% of infants were infected and there was no significant difference in the rate of transmission between Europe and the US despite the different approaches to treatment and delivery.
  
  
  CONCLUSIONS
  These findings confirm that there are important historical differences between the HIV-infected pregnant populations in Western Europe and the USA, both in terms of the characteristics of the women and their obstetric and therapeutic management. Although highly active antiretroviral therapy predominates in pregnancy in both settings now, population differences are likely to remain.
  
  
  BACKGROUND
  NCT00000869.
authors.affiliation: Centre of Paediatric Epidemiology and Biostatistics, Institute of Child Health, University College London, UK. m.newell@ich.ucl.ac.uk
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Newell
authors.forename: Sharon
authors.initials: S
authors.lastname: Huang
authors.forename: Simona
authors.initials: S
authors.lastname: Fiore
authors.forename: Claire
authors.initials: C
authors.lastname: Thorne
authors.forename: Laurent
authors.initials: L
authors.lastname: Mandelbrot
authors.forename: John L
authors.initials: JL
authors.lastname: Sullivan
authors.forename: Robert
authors.initials: R
authors.lastname: Maupin
authors.forename: Isaac
authors.initials: I
authors.lastname: Delke
authors.forename: D Heather
authors.initials: DH
authors.lastname: Watts
authors.forename: Richard D
authors.initials: RD
authors.lastname: Gelber
authors.forename: Coleen K
authors.initials: CK
authors.lastname: Cunningham
mesh_terms: D000022:Abortion, Spontaneous; D000328:Adult; D023241:Antiretroviral Therapy, Highly Active / Q000706:statistics & numerical data*; D002585:Cesarean Section; D015331:Cohort Studies; D005060:Europe / Q000453:epidemiology; D005260:Female; D005865:Gestational Age; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000635:transmission*; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control* / Q000706:statistics & numerical data; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000821:virology*; D011256:Pregnancy Outcome; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D019562:Viral Load