With HIV prevalence among women increasing, more provinces encourage prenatal testing

Ann Silversides

CMAJ 1998;158:1518-9

[ en bref ]

© 1998 Ann Silversides (full text / en bref)

• Evidence: Evidence-based guidelines for universal counselling and offering of HIV testing in pregnancy in Canada
• Editorial: Access to prenatal HIV testing

Testing of pregnant women for antibodies to HIV remains a thorny medical and ethical issue. On the one side are children who stand to benefit if their mothers' HIV status is determined. On the other is women's right to determine what tests they will receive. A majority of provinces now have counselling programs in place to encourage women to undergo testing. However, testing remains voluntary and informed consent is required before a test is done — policies that have CMA support.

Les examens de dépistage des anticorps du VIH chez les femmes enceintes demeurent une question médicale et éthique épineuse. D'un côté, des enfants pourraient en bénéficier si l'on détermine l'état de leur mère face au VIH. De l'autre, les femmes ont le droit de choisir les tests qu'elles subiront. Une majorité de provinces ont maintenant des programmes de counselling pour encourager les femmes à subir un test. Les tests demeurent toutefois volontaires et il faut obtenir le consentement éclairé de l'intéressée avant de procéder à un test. L'AMC appuie ces politiques.

Meanwhile, Health Canada is conducting a national survey of physicians' attitudes toward counselling of pregnant women and is researching women's perceptions of risk and HIV, said Julia Martin, national prevention coordinator for HIV/AIDS. As well, a background paper on legal and ethical issues has been prepared. "Essentially, we're funding things the provinces might have difficulty funding, and collecting information to help them implement or alter their programs."

The prevalence rate for HIV infection among women is increasing in most provinces, with the vast majority of infected women being of childbearing age. In April, Health Canada reported that 21.5% of HIV-positive test results in 1996 involved women, compared with 19.4% in 1995 and 9.8% between 1985 and 1994.

However, the main catalyst for the provincial programs was not these rising numbers but the 1994 publication of research showing that the perinatal transmission of HIV could be reduced by two-thirds if pregnant woman who are infected are treated with zidovudine; the risk of perinatal transmission stands at about 25% without any pharmaceutical intervention.

Researchers say the transmission rate has been reduced even further with the use of the now standard-of-practice treatment protocol involving combination drug therapy and the use of protease inhibitors.

Canada's most populous province is a noticeable and notable exception when it comes to counselling and testing programs for pregnant women. Ontario's provincial laboratory reports that only about 12% of the province's pregnant women take HIV tests, compared with an estimated 80% in British Columbia. (In the fall of 1994, BC became the first province to introduce routine counselling and routine offers of testing.)

In a background document supplied to the College of Physicians and Surgeons of Ontario, the Ontario Ministry of Health acknowledges that if it had had a screening program in place, 13 new infections could have been prevented in 1996 alone. A 1997 study found that the prevalence rate of HIV infection among Ontario women of childbearing age — 0.6/1000 — is 3 times higher than it was in 1992. (Earlier this year the college council voted to support a policy for prenatal testing for HIV infection "as proposed by the Ministry of Health," but to date no program has been approved.)

Quebec introduced a program of universal counselling and voluntary testing in May 1997, said Dr. Danielle Auger, a physician consultant at Quebec's AIDS coordination centre.

She said the Quebec kit, which includes extensive information and guidance for doctors, and pamphlets for patients, has been adopted by some European countries and is being used by Nova Scotia to develop its program. "We feel strongly that HIV counselling has to be done in the first visit because of time limits — we want to give women the choice of an abortion."

In the first 10 months of its program, Quebec identified 15 pregnant women who did not know they were HIV positive, said Dr. Auger.

Research by Dr. Robert Remis, an epidemiologist with the University of Toronto's Department of Public Health Sciences, indicates that only about 25% of pregnant Ontario women infected with HIV know they have contracted the virus. And if they haven't been diagnosed, HIV-positive mothers who have given birth to children with HIV may not know their status for years. Research by Dr. Susan King, a pediatrician and infectious disease specialist at Toronto's Hospital for Sick Children, indicates that only 20% of infected children become ill and are brought to the attention of doctors in their first year.

Ontario's current policy, articulated in a 1995 statement by the province's medical officer of health, states that doctors should recommend HIV testing to women at high risk. But Dr. David Patrick, associate director of STD/AIDS control at the BC Centre for Disease Control, says doctors have not proven themselves to be very accurate when it comes to identifying women at high risk.

Meanwhile, many doctors take issue with the continued emphasis on risk groups. "It's not about groups, it's about behaviour," notes Dr. Anne Phillips, director of the HIV program at St. Michael's Hospital in Toronto.

In both the Alberta and Newfoundland programs, HIV tests are listed among the routine tests on standard prenatal care check lists — this is the "opt-out" notion. (Although BC has a checklist on its standard prenatal form, the boxes to be ticked answer the questions "has HIV testing been discussed" and "has HIV testing been done.")

The opt-out option is controversial because of concern that it might increase the risk that busy doctors will do little or no counselling, and hence fail to meet the requirement for informed consent, said Health Canada's Martin. HIV cannot be considered a routine test because the impact of a positive test can be so devastating, she added.

Key AIDS organizations support universal counselling and voluntary testing but, like the Canadian HIV/AIDS Legal Network, stress the necessity of good pre- and post-test counselling. Lawyer Louise Shap, who has written extensively on this topic, notes that the success of provincial programs is measured by increases in the number of pregnant women who are tested. "Let's not see that as the be-all and end-all. I think we have to go one step back and recognize that prevention starts with preventing women from becoming positive in the first place."

For a pregnant woman, a positive test result only marks the beginning. It can be the first step into complicated drug therapies and marginalization, and into the face of many tough issues. For instance, what will happen to the children of HIV-positive mothers who become ill?

Phillips has some experience with this through her work at St. Michael's Hospital. "Women are the centres of the family unit. So when a woman is sick with HIV, the whole family falls apart. . . . I have seen so many family units disintegrate, whether the children are infected or not. There is enormous social loss and destruction."

Health Canada says the concept of offering voluntary HIV testing to all pregnant women has been endorsed by the CMA, the Society of Obstetricians and Gynaecologists of Canada, the College of Family Physicians of Canada and the Quebec College of Physicians. The CMA has discussed the issue several times at both its General Council and board meetings. It made its most recent declaration in March 1997 when the Board of Directors reiterated that a "patient's informed consent must be obtained prior to testing."

The CMA's Counselling Guidelines for HIV Testing also make this clear: "If the woman has chosen to be tested," they tell doctors, "obtain and record receipt of informed consent." [The most thorough guidelines yet developed on HIV screening in pregnancy appear in this issue, page 1449.]

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