Testing of antenatal women

Pregnant women have been the target of many seroprevalence studies, as they provide an accessible cohort for HIV testing and a stable sampling frame^{19,23,22,310,311}. While valuable information has been obtained on trends in the epidemic, the practice of testing in pregnancy has been criticized in the past, as one which stigmatizes women and which has not led to implementation of appropriate health strategies^312,313.

With increasing knowledge about HIV and about mother-to-child transmission in particular, the focus has moved from the possible public health benefits of testing in pregnancy to the potential benefits for the individual woman^314,315. This has re-emphasized the need for the provision of appropriate facilities for testing and counselling^{126,277,316,317,318,319,320,321,322,323,324}. Voluntary testing of pregnant women is recommended and offered in many countries^{17,325,326,327}. The introduction of testing programmes has increased the number of identified HIV positive women in many centres³²⁸. Despite this, identification of infected women may not be optimal if women do not access antenatal care, or where counselling and testing services are inadequate^{262,327,329,330,331,332,333}.

Wherever possible, voluntary counselling and testing should be available to any pregnant woman who requests it and offered to all in areas of moderate or high prevalence. Routine testing of pregnant women without consent or without access to counselling is, however, an unacceptable practice and the disadvantages may negate any benefit obtained from knowing the HIV status of the women. These include a reluctance to utilize maternity services through fear of discrimination, denial of a positive diagnosis and stigmatization. Recent discussion about, and recommendations for mandatory testing of pregnant women or newborns have led to concern about the autonomy and rights of women^315,329.

There are, however, a number of potential benefits to women of voluntary HIV testing prior to or during pregnancy. This is the case even in the absence of expensive interventions such as long-course antiretroviral therapy. These benefits include:

1 Where a woman is found to be infected, this knowledge can facilitate early counselling and treatment.

2 A diagnosis in the mother allows appropriate treatment and follow-up of her child.

3 Knowledge of her HIV status enables the woman to take decisions on continuation of the pregnancy and on future fertility.

4 Testing allows an opportunity to implement strategies to attempt to prevent transmission to the child.

5 Knowledge of HIV status enables the woman to take precautions to help prevent transmission to sexual partners.

6 Women diagnosed as HIV positive can tell their sexual partners and enable partners to be counselled and tested.

7 If the test result is negative, women can be guided in appropriate HIV prevention measures and risk reduction behaviour.

Balanced against these advantages are the possible disadvantages of HIV testing in pregnancy. These will vary from community to community, but reports have described an increase in the risk of violence against women; the possibility that the woman may be stigmatized within her community and by health workers; higher levels of anxiety and psychological sequelae; and concerns about the additional work load for maternity services^{334,335,336,337}. Several studies have described the reluctance of some women to return for their test results³³⁷,³³⁸'³³⁹. In Nairobi, 5.9% of HIV-positive women reported violence related to the HIV test result. After changing to a policy of giving results out only on request, only 35% of women who had agreed to testing returned to ask for results³³⁷. In Kigali, 63.9% of positive women and 71.3% of HIV-negative women returned for test results and the only variable found to be associated with failure to return for counselling was a positive HIV test³³⁸.

Women should be encouraged to bring their sexual partner(s) for counselling and testing wherever possible. However, very few testing services have managed to achieve much success in this regard^336,338. The best predictor of return for counselling by women in one US study was the time spent in counselling women and the counsellor's skills³³⁹. Voluntary counselling and testing (VCT) services for couples, preconceptual counselling and testing services not linked to antenatal care may increase testing uptake. However, it must be emphasized that, unless people have real choices for action once they have their test results (i.e. access to affordable services such as mother-to-child transmission preventive interventions, and care and support services), there is no good reason to take a test (see: Counselling and voluntary HIV testing for pregnant women in high HIV prevalence countries: Guidance for service providers (UNAIDS, May 1999))

A qualified person should take the blood specimen for an HIV test, using "universal precautions" against accidental transmission in all cases. These must include the safe disposal of needles and syringes. The type of tests used will depend upon local seroprevalence, policy and available facilities. In most cases blood specimens will be sent to the appropriate laboratory, but in some areas, dry blood spot testing may be an acceptable alternative. The first line test for HIV-antibodies is an enzyme-linked immuno-absorbent assay (ELISA) test, or a rapid test algorithm. Depending on local conditions, a confirmatory test with a second ELISA or rapid test using a different test kit, or a Western Blot should be performed. Any testing strategy must be undertaken with appropriate laboratory quality assessment³⁴⁰,³⁴¹.

With increasingly sensitive and specific simple and "rapid" tests becoming available, on-site testing may become more feasible (see The importance of simple/rapid assays in HIV testing. WHO/UNAIDS recommendations; WER 1998, 73, 321-328). Recent reports of the use of "same-day" rapid test results in a rural hospital in a resource-poor setting and in an urban STI clinic have suggested that this is an acceptable and appropriate intervention³⁴²,³⁴³. Preliminary reports of the use of dual rapid tests for same day diagnosis in antenatal clinics suggest that this is an appropriate and acceptable way to provide testing in this setting. The major advantage is that early results enable more women to access antenatal strategies for the prevention of mother-to-child transmission.