• anti-HIV agents;
  • HIV infections;
  • infant;
  • vertical infectious disease transmission;
  • newborn;
  • post-exposure prophylaxis


To investigate changing clinical practice with regard to antiretroviral post-exposure prophylaxis (PEP) and factors associated with the use of combination prophylaxis in infants born to HIV-infected women in the UK and Ireland.


Surveillance of obstetric and paediatric HIV infection in the UK and Ireland is conducted through the National Study of HIV in Pregnancy and Childhood. Infants born to HIV-infected women between 2001 and 2008 were included in the study.


Ninety-nine per cent of infants (8155 of 8205) received antiretroviral prophylaxis; 86% of those with information on type of prophylaxis (n=8050) received single, 3% dual and 11% triple drug prophylaxis. Among those who received prophylaxis, use of triple prophylaxis increased significantly between 2001–2004 and 2005–2008, from 9% (297 of 3243) to 13% (624 of 4807) overall (P<0.001); from 43% (41 of 95) to 71% (45 of 63) in infants born to untreated women; and from 13% (114 of 883) to 32% (344 of 1088) where mothers were viraemic despite highly active antiretroviral therapy (HAART) in pregnancy. In multivariable analysis, factors associated with receipt of triple prophylaxis included later time period, shorter duration or lack of antenatal antiretroviral therapy, receipt of antiretroviral drugs during labour, detectable maternal viral load, CD4 count<200 cells/μL in pregnancy, preterm delivery (<37 weeks) and unplanned (emergency caesarean or vaginal) delivery.


Between 2001 and 2008, almost all infants born to HIV-infected women in the UK and Ireland received antiretroviral PEP, mostly with one drug. Use of triple PEP increased over time, particularly for infants whose mothers were untreated or viraemic despite HAART, in line with current guidelines.