Published: 30 June 2012
  • Testing has been routine in UK antenatal settings since 1999, and is considered a major success in testing policy.
  • Women at continued high risk of HIV infection may be offered a repeat test in the third trimester.


Since 1999 it has been routine for pregnant women in the UK to be offered an HIV test. The test was introduced in recognition of the fact that there are effective methods of preventing vertical transmission and effective treatments for adults.

In the mid-1990s only about one-third of infected pregnant women were diagnosed, and most of those were aware of their infection status before they became pregnant.1

Debate about how the test should be offered was influenced by two studies in Edinburgh, where different methods were compared. The first, randomised study found that uptake of testing was 6% when testing information was provided in leaflets, but rose to 35% when a midwife directly offered the test.2 The uptake of testing varied between midwives, suggesting that midwives' own attitudes towards offering the test affected the response of patients. It was also found that routine testing did not provoke any more anxiety amongst pregnant women than other routine blood tests offered during pregnancy.

That study used an opt-in approach (women had to make an active choice to be tested), and some women felt that to opt in would indicate high-risk behaviour. The second study3 assessed an opt-out approach (midwives offered the test orally, emphasising its benefits, the fact that it was routine, and the possibility that women could opt out if they wished). In this study, 88% of women accepted the offer of a test. 

In 1999, the government announced that HIV testing would be offered and recommended routinely to all pregnant women in the UK, and this policy was fully implemented by 2003.

This is often cited as a major success in testing policy: there has been a significant reduction in the proportion of HIV infections that remain undiagnosed before delivery; and women who are tested antenatally have a higher median CD4 count at diagnosis than other women and heterosexual men, which would indicate that efforts to detect HIV infection in people without symptoms will result in earlier diagnosis, reduced morbidity and mortality, and less onward transmission.

There have been cases of women who have tested negative early in their pregnancy, but were either tested during the window period or seroconverted during pregnancy or while breastfeeding, and subsequently passed their infection onto their baby (a high viral load in acute infection is likely to be a contributory factor).4,5 BHIVA pregnancy guidelines suggest that in specific cases where a woman is at continued high risk of HIV infection, it may be appropriate for her to be offered a further HIV test during the third trimester.6

To deal with the same problem, American researchers have argued that as well as retesting during the third trimester, pooled RNA tests should be used. These have a significantly shorter window period: in North Carolina 3.4% of positive women would have had their diagnosis missed if only antibody tests were used.7 

BHIVA guidelines also recommend that if a woman arrives for labour without previous contact with antenatal services, a rapid test should be offered.

Routine testing does means that some woman will receive their diagnosis in pregnancy. For a newly diagnosed pregnant woman her HIV diagnosis is likely to be shocking and will provoke anxiety. She will have concerns about her health, the health of her baby and the HIV status of her partner. Women in this situation will be required to make complex decisions about treatment, prevention of mother-to-child transmission and – potentially – disclosure of her status to her baby’s father. She should be offered care from an obstetrician experienced in this field and an HIV consultant.


  1. Intercollegiate Working Party Reducing Mother-to-Child Transmission of HIV Infection in the United Kingdom., 2006
  2. Simpson WM et al. Uptake and acceptability of antenatal HIV testing: randomised controlled trial of different methods of offering the test. BMJ 316:262-267, 1998
  3. Simpson WM Antenatal HIV testing: assessment of a routine voluntary approach Br Med J 318: 1660-1661, 1999, 1999
  4. Jayasuriya A et al. HIV and pregnancy – are we doing enough? BMJ 334: 1287-1288, 2007
  5. Humphrey JH et al. Mother to child transmission of HIV among Zimbabwean women who seroconverted postnatally: prospective cohort study BMJ 341:c6580, 2010
  6. de Ruiter A et al. British HIV Association and Children's HIV Association guidelines for the management of HIV infection in pregnant women 2008. HIV Med 9: 452-502. Available online at, 2008
  7. Patterson KB et al. Frequent detection of acute HIV infection in pregnant women. AIDS 21(17): 2303-2308, 2007
This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.
Community Consensus Statement on Access to HIV Treatment and its Use for Prevention

Together, we can make it happen

We can end HIV soon if people have equal access to HIV drugs as treatment and as PrEP, and have free choice over whether to take them.

Launched today, the Community Consensus Statement is a basic set of principles aimed at making sure that happens.

The Community Consensus Statement is a joint initiative of AVAC, EATG, MSMGF, GNP+, HIV i-Base, the International HIV/AIDS Alliance, ITPC and NAM/aidsmap

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member of your healthcare team for advice tailored to your situation.