Screening for HIV in pregnancy enables measures to be taken to reduce the risk of mother-to-child transmission and for the woman to be offered treatment and psychosocial support.
8.1.1 BackgroundHuman immunodeficiency virus (HIV) is a blood-borne infection that is initially asymptomatic but involves gradual compromise of immune function, eventually leading to acquired immunodeficiency syndrome (AIDS). The time between HIV infection and development of AIDS ranges from a few months to as long as 17 years in untreated patients (PHLS 1998). Undiagnosed HIV infection during pregnancy has serious implications for the health of both the woman and her child. Early HIV diagnosis can reduce the risk of mother-to-child transmission and the rate of disease progression in the mother (NICE 2008).
HIV in Australia
- Rates of diagnosis of HIV — Over the period 2006–2009, new HIV diagnoses in Australia remained relatively stable at around 1,000 a year (NCHECR 2010a). The rate of HIV diagnosis was considerably higher in men (86.7%) (NCHECR 2010a). The population rate of diagnosis was similar for Aboriginal and Torres Strait Islander and non-Indigenous populations, with a rate of 4 and 5 per 100,000, respectively (NCHECR 2010b). However, among Aboriginal and Torres Strait Islander peoples a higher proportion of infections was attributed to injecting drug use (20% vs 3% for non-Indigenous) and a higher proportion of infections was among women (25.5% vs 7.3% for non-Indigenous) (NCHECR 2010b).
- Geographical distribution — Trends in new diagnoses differ across jurisdictions, with rates in NSW, WA, Tasmania and the ACT remaining relatively stable and increases in Queensland, SA, NT and Victoria (NCHECR 2010a). In 2009, the rate of HIV diagnosis was highest among people resident in major cities in both the Aboriginal and Torres Strait Islander population and the non-Indigenous population (NCHECR 2010b). The rate of HIV diagnosis in the Aboriginal and Torres Strait Islander population was 10 per 100,000 in major cities compared to 1 per 100,000 in very remote areas.
- Country of origin — Rates of HIV diagnosis among people from other regions of birth have increased, with at least a doubling of rates among people born in sub-Saharan Africa, Asia, South/Central America and the Caribbean, and Oceania (other than Australia) (NCHECR 2010a).
- Risk factors — Recognised risk factors include having a history of intravenous drug taking or sexual partners who have injected drugs or have HIV, and/or residence in a country where HIV is endemic (Brocklehurst 2000).
- Perinatal exposure — In Australia, identified perinatal HIV exposure has risen from 2.3 per 100,000 live births in 1982–86 (McDonald et al 2009) to 12.3 per 100,000 live births in 2008–09 (NCHECR 2010a).
Risks associated with HIV infection in pregnancyGlobally, the vast majority of children with AIDS acquire infection as a result of mother-to-child transmission during pregnancy, during birth or through breastfeeding (Volmink et al 2007). Maternal viral load is a strong independent determinant of transmission risk (Khouri et al 1995; Mofenson 1995; John & Kreiss 1996; Warszawski et al 2008).
In developed countries the rate of mother-to-child transmission is 14–25% (Branson et al 2006). In Australia, the mother-to-child transmission rate among children whose mothers were diagnosed antenatally has declined significantly, from 25% in 1987–1990 to 5% in 2003–2006 (McDonald et al 2009). The rate declined from 8% in 1987–1998 to 1% in 1999–2006 among children whose mother used at least two interventions. Mother-to-child transmission remained high among children born to women diagnosed postnatally (50%) and women diagnosed antenatally who used no interventions.
8.1.2 Screening for HIV infection in pregnancy
Summary of the evidenceUniversal screening for HIV in pregnancy is recommended in the United Kingdom (de Ruiter et al 2008; NICE 2008; RCOG 2010), the United States (Branson et al 2006) and Canada (SOGC 2006; CPS 2008). The Australian Department of Health and Ageing also recommends that all women be routinely offered HIV screening in the first trimester (DoHA 2006). These policies are based on the availability of accurate diagnostic tests and effectiveness of antiretroviral treatment in preventing mother-to-child transmission. They also reflect the fact that screening based on risk factors would miss a substantial proportion of women with HIV (Chou et al 2005).
Diagnostic accuracy of testsTests for HIV diagnosis in pregnant women include:
- standard tests — the enzyme immunoassay and Western blot protocol is highly (>99%) sensitive and specific (Samson & King 1998; Butlerys et al 2004; Chou et al 2005; Chappel et al 2009); and
- rapid HIV tests,1 which have similar accuracy (Butlerys et al 2004; Chou et al 2005) and provide results within hours without requiring a return visit (Tepper et al 2009), with blood-based tests having greater sensitivity than tests using oral fluids (Pai et al 2007).
Interventions to prevent mother-to-child transmission
Cochrane reviews into the effectiveness of interventions in preventing mother-to-child transmission have found that:
- short courses of certain antiretroviral medicines are effective and are not associated with any safety concerns in the short term (Volmink et al 2007);
- caesarean section before labour and before ruptured membranes is effective among women with HIV not taking antiretrovirals or taking only zidovudine (Read & Newell 2005);
- vitamin A supplementation is not effective in preventing transmission (Wiysonge et al 2011);
- there is no evidence of an effect of vaginal disinfection (Wiysonge et al 2005);
- complete avoidance of breastfeeding is effective in preventing mother-to-child transmission of HIV (Horvath et al 2009); and
- if breastfeeding is initiated, the combination of exclusive breastfeeding during the first few months of life and extended antiretroviral prophylaxis to the infant is effective (Horvath et al 2009).
Recommended interventions appear to be acceptable to pregnant women and are associated with mother-to-child transmission rates of 1% to 2% (Chou et al 2005). In Australia between 1982 and 2005, uptake of interventions to reduce mother-to-child transmission of HIV was high (Giles et al 2008).
Recommendation - Grade B11. Routinely offer and recommend HIV testing at the first antenatal visit as effective interventions are available to reduce the risk of mother-to-child transmission.
Practice pointm. A system of clear referral paths ensures that pregnant women who are diagnosed with an HIV infection are managed and treated by the appropriate specialist teams.
Pre-test and post-test discussionsPre- and post-test discussions are an integral part of HIV testing.
Considerations before testingProviding information and support associated with testing aims to minimise the personal and social impact of HIV infection (DoHA 2006). The Australian Department of Health and Ageing HIV testing guidelines recommend that (DoHA 2006):
- antenatal testing only be performed with the informed consent of the woman;
- all women contemplating pregnancy or seeking antenatal care be made aware of the benefits of diagnosis of HIV infection and management, and prevention strategies available for both the mother and the baby;
- women receive materials (in written and other formats) outlining the tests that will be offered antenatally and explaining the testing procedure;
- women with limited literacy or for whom English is a second language receive appropriate educational resources (eg using media such as video, audio, multimedia or in languages other than English); and
- women with a first language other than English be offered access to accredited interpreting services.
Considerations after testing
- Women who accept testing may experience anxiety while waiting for the initial test result or while waiting for results of repeat testing.
- Unexpected detection of HIV can result in distress, which is exacerbated in the context of pregnancy. Health professionals delivering the test result should use their best judgement when deciding the most appropriate way to deliver the test result (DoHA 2006).
Screening in rural and remote areasRapid tests improve the availability of HIV testing in situations where there is limited access to pathology services and returning for results may be difficult (DoHA 2006). However, the use of these tests should be limited to situations where (DoHA 2006):
- testing is conducted in, or backed up by, a clinical setting;
- testing is conducted under the auspice of a National Association of Testing Authorities/Royal College of Pathologists of Australia medical testing accredited laboratory;
- reliable Therapeutic Goods Administration approved rapid tests are available;
- high quality information on the tests and their use is available and provided;
- the health professional performing the test is suitably trained in conducting and interpreting the test and has the skills to provide pre and post-test information/discussion (if conducted outside an accredited laboratory); and
- quality assurance programs are available to ensure ongoing competency of healthcare professionals performing the tests.
Considerations beyond the first trimester
- Rapid HIV testing12 of women who are late in antenatal booking or who present in labour with undocumented HIV status.
8.1.3 Practice summary — HIV screeningWhen — Early in antenatal care
Who — Midwife; GP; obstetrician; Aboriginal and Torres Strait Islander health worker; multicultural health worker
- Discuss HIV screening — Explain that it is important to find out whether a woman has HIV because of the risk of transmission to the baby. Testing also gives the woman the opportunity to receive appropriate treatments.
- Document and follow-up — Note the results of HIV screening in the woman’s record and have a follow-up system in place so women who have HIV have access to counselling to discuss the test results and available interventions to prevent transmission during pregnancy.
- Take a holistic approach — If a woman is found to have HIV, specialist advice on management is required. Other considerations include psychosocial support, contact tracing, partner testing, testing for other sexually transmitted infections and continuing follow-up.
8.1.4 ResourcesDoHA (2006) National HIV Testing Policy 2006. Canberra: Australian Government Department of Health and Ageing. For more information please visit National HIV Testing Policy 2006.
RCOG (2010) Green Top Guideline no 39 Management of HIV in Pregnancy. London: Royal College of Obstetricians and Gynaecologists. For more information please visit Royal College of Paediatrics and Child Health website.
8.1.5 ReferencesBoxall EH & Smith N (2004) Antenatal screening for HIV; are those who refuse testing at higher risk than those who accept testing? J Public Health 26(3): 285–87.
Branson BM, Handsfield HH, Lampe MA et al (2006) Revised recommendations for HIV testing of adults, adolescents, and pregnant women in health-care settings. Department of Health and Human Services Centers for Disease Control and Prevention, United States. MMWR 55 (No RR-14): 1–17.
Briand N, Mandelbrot L, Le Chenadec J et al (2009) No relation between in-utero exposure to HAART and intrauterine growth retardation. AIDS 23(10): 1235–43.
Brocklehurst P (2000) Interventions aimed at decreasing the risk of mother-to-child transmission of HIV infection. Cochrane Database of Systematic Reviews (2):CD000102, 2000.
Bulterys M, Jamieson DJ, O’Sullivan MJ et al (2004) Rapid HIV-1 testing during labor: a multicenter study. Mother-Infant Rapid Intervention At Delivery (MIRIAD) Study Group. JAMA 292(2): 219–23.
Chappel RJ, Wilson KM, Dax EM (2009) Immunoassays for the diagnosis of HIV: meeting future needs by enhancing the quality of testing. National Serology Reference Laboratory Australia, Fitzroy, Victoria. Aust Future Microbiol 4(8): 963–82.
Chou R, Smits AK, Huffman LH et al (2005) A review of the evidence for the U.S. Preventive Services Task Force. Annal Int Med 143(1): 38–54.
CPS (2008) Testing for HIV infection in pregnancy. Infectious Diseases and Immunization Committee, Canadian Paediatric Society (CPS). Paediatric Child Health 13(3): 221–24.
De Ruiter A, Mercey D, Anderson J et al (2008) British HIV Association and Children’s HIV Association guidelines for the management of HIV infection in pregnant women 2008. HIV Med 9(7): 452–502.
DoHA (2006) National HIV Testing Policy 2006. Canberra: Australian Government Department of Health.
Ferguson W, Cafferkey M, Walsh A et al (2008) Targeting points for further intervention: a review of HIV-infected infants born in Ireland in the 7 years following introduction of antenatal screening. J Int Assoc Physicians AIDS Care 7(4): 182-86.
Giles M, McDonald AM, Elliott EJ et al (2008) Variable uptake of recommended interventions to reduce mother-to-child transmission of HIV in Australia, 1982–2005. Med J Aust 189: 151–54.
Horvath T, Madi BC, Iuppa IM et al (2009) Interventions for preventing late postnatal mother-to-child transmission of HIV. Cochrane Database of Systematic Reviews 2009, Issue 1. Art. No.: CD006734. DOI: 10.1002/14651858.CD006734.pub2.
John GC & Kreiss J (1996) Mother-to-child transmission of human immunodeficiency virus type 1. Epidemiol Rev 18: 149–57.
Khouri YF, McIntosh K, Cavacini L et al (1995) Vertical Transmission of HIV-1. Correlation with maternal viral load and plasma levels of CD4 binding site antigp120 antibodies. J Clin Invest 95: 732–37.
Kourtis AP, Schmid CH, Jamieson DJ et al (2007) Use of antiretroviral therapy in pregnant HIV-infected women and the risk of premature delivery: a meta –analysis. AIDS 21(5): 607–15
McDonald AM, Zurynski YA, Wand HC et al (2009) Perinatal exposure to HIV among children born in Australia, Med J Aust 190(8): 416–20.
Mofenson LM (1995) A critical review of studies evaluating the relationship of mode of delivery to perinatal transmission of human immunodeficiency virus. Pediatr Infect Dis J 14: 169–76.
NCHECR (2010a) Annual Surveillance Report. National Centre for HIV Epidemiology and Clinical Research. Sydney: University of New South Wales.
NCHECR (2010b) Bloodborne Viral and Sexually Transmitted Infections in Aboriginal and Torres Strait Islander People: Surveillance and Evaluation Report 2010. Sydney: National Centre in HIV Epidemiology and Clinical Research, The University of New South Wales.
NICE (2008) Antenatal Care. Routine Care for the Healthy Pregnant Woman. National Collaborating Centre for Women’s and Children’s Health. Commissioned by the National Institute for Health and Clinical Excellence. London: RCOG Press.
Pai NP, Tulsky JP, Cohan D et al (2007) Rapid point-of-care HIV testing in pregnant women: a systematic review and meta-analysis. Trop Med Int Health 12(2): 162–73.
PHLS (1998) Report to the National Screening Committee. Antenatal Syphilis Screening in the UK: A Systematic Review and National Options Appraisal with Recommendations. STD Section, HIV and STD Division, PHLS Communicable Disease Surveillance Centre, with the PHLS Syphilis Working Group. London: Public Health Laboratory Service.
Plitt SS, Singh AE, Lee BE et al (2007) HIV seroprevalence among women opting out of prenatal HIV screening in Alberta, Canada: 2002-2004. Clin Infect Dis 45(12): 1640–43.
RCOG (2010) Green Top Guideline no 39 Management of HIV in Pregnancy. London: Royal College of Obstetricians and Gynaecologists. For more information please visit UK Royal College of Obstetricians and Gynaecologists website.
Read JS & Newell ML (2005) Efficacy and safety of cesarean delivery for prevention of mother-to-child transmission of HIV-1. Cochrane Database of Systematic Reviews 2005, Issue 4.
Samson L & King S (1998) Evidence-based guidelines for universal counselling and offering of HIV testing in pregnancy in Canada. Can Med Assoc J 158:1449–57.
SOGC (2006) HIV screening in pregnancy. Maternal fetal Medicine Society, Society of Obstetricians and Gynaecologists of Canada. J Obstet Gynaecol Can 28(12): 1103–07.
Struik SS, Tudor-Williams G, Taylor GP et al (2008) Infant HIV infection despite “universal” antenatal testing. Arch Dis Childhood 93(1): 59–61.
Tepper NK, Farr SL, Danner SP et al (2009) Rapid human immunodeficiency virus testing in obstetric outpatient settings: the MIRIAD study. Am J Obstet Gynecol 201(1): 31.e1-6.
Townsend CL, Willey BA, Cortina-Borja M et al (2009) Antiretroviral therapy and congenital abnormalities in infants born to HIV-infected women in the UK and Ireland, 1990-2007. AIDS 23(4): 519–24.
Volmink J, Siegfried N, van der Merwe L et al (2007) Antiretrovirals for reducing the risk of mother-to-child transmission of HIV infection. Cochrane Database of Systematic Reviews 2007, Issue 1. Art. No.: CD003510. DOI: 10.1002/14651858. CD003510.pub2.
Warszawski J, Tubiana R, Le Chenadec J et al (2008) Mother-to-child HIV transmission despite antiretroviral therapy in the ANRS French Perinatal Cohort. AIDS 22(2): 289–99.
Wiysonge CS, Shey M, Kongnyuy EJ et al (2011) Vitamin A supplementation for reducing the risk of mother-to-child transmission of HIV infection. Cochrane Database of Systematic Reviews 2011, Issue 1. Art. No.: CD003648. DOI: 10.1002/14651858.CD003648.pub3.
Wiysonge CS, Shey M, Shang J et al (2005) Vaginal disinfection for preventing mother-to-child transmission of HIV infection. Cochrane Database of Systematic Reviews 2005, Issue 4. Art. No.: CD003651. DOI: 10.1002/14651858. CD003651.pub2.