An audit of obstetricians’ management of women potentially infected with blood-borne viruses

A high proportion of women who are infected with blood-borne viruses such as hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV are in their childbearing years. There has been debate in the literature about the issue of antenatal screening for HIV in Australia1 and about the variability of recommendations in Australian protocols and national policies about screening for HCV and HIV.2 An important first step in addressing these issues is to examine current practices of obstetricians in Australia and to compare these with current recommendations (for a summary of principal recommendations see Box 4). The purpose of our project was to audit current antenatal screening practices for HBV, HCV and HIV; to assess knowledge regarding interventions during labour that may influence vertical transmission; and to assess knowledge regarding transmission via breastfeeding.

Statistical analysis. Statistical analysis involved standard frequency tests and χ2 tests using an SPSS statistical program.3

Ethics approval. According to guidelines developed by the Clinical Ethics Advisory Group and the Research Ethics Committee of the Royal Women’s Hospital, our study did not require formal ethics approval, as it was an audit of current practice rather than a clinical research project.

Antenatal screening and assessment of risk factors. Current antenatal screening practices and the level of assessment of risk factors for exposure to blood-borne viruses are summarised in Box 1. Although 97% of obstetricians said they would always screen pregnant women for HBV, only 51% always offered screening for HIV and 60% always offered screening for HCV.

Only about 20% of obstetricians claimed that they always ask pregnant women about risk factors for exposure to blood-borne viruses.

Clinical management. Aspects of clinical management of pregnant women with blood-borne viruses are summarised in Box 2. The majority of obstetricians said they would usually or always avoid fetal scalp monitoring in women with HBV, HCV or HIV. Of note, only 36% of respondents said they would always recommend elective caesarean section to HIV-infected women, and only 33% would always avoid rupture of membranes.

Risk of viral transmission through breastfeeding. Asked whether they would discuss the risk of viral transmission through breastfeeding with a patient who had a blood-borne virus, the proportion of obstetricians who claimed they would always do so was 55% (for HBV), 67% (for HCV) and 82% (for HIV). Despite a lack of evidence, 34% of respondents would advise women that breastfeeding is associated with an increased risk of HBV transmission, and 47% would advise women of an increased risk of HCV transmission with breastfeeding (Box 3).

Our survey is the largest study to date to assess the current knowledge and practice of Australian obstetricians in relation to women infected with blood-borne viruses. The current “best practice” for blood-borne virus screening in pregnant women is far from clear, with wide variation across Australia.2 There is some discordance between current antenatal screening practice and the RANZCOG recommendations.4 The possible reasons for this may include a lack of knowledge of the RANZCOG guidelines and/or a belief by some clinicians that current guidelines do not reflect best practice. The variation in recommendations according to virus type may also cause some confusion.

HBV. The screening and clinical management of women infected with HBV is in keeping with current guidelines (Box 4). However, it is of concern that a substantial proportion of obstetricians are giving incorrect advice about the risk of transmission through breastfeeding.

HCV. It is noteworthy that obstetricians were more likely to screen pregnant women for HCV than for HIV, despite less evidence for the effectiveness of interventions to reduce perinatal transmission of HCV.

This may be because of presumed higher seroprevalence of HCV in the community (the current seroprevalence of HIV in the unscreened antenatal population is unknown). Alternatively, obstetricians may see pregnancy as an opportunity to identify asymptomatic women before the development of long-term complications of HCV infection, such as cirrhosis and hepatocellular carcinoma. Effective treatment options, which are more likely to be successful if commenced before the development of cirrhosis, are now available and can be considered for many HCV-infected women after pregnancy and breastfeeding.15

Studies have shown that up to 40% of women found to be HCV-positive during pregnancy screening have no identifiable risk factor. Universal screening would assist in identifying these women.16 Furthermore, during the postpartum period women may be more likely to attend follow-up appointments and adhere to treatment.17 The disadvantages of a universal screening approach include the cost to the healthcare system of testing all women, given that there is little evidence that intervening during pregnancy affects the rate of vertical transmission. Moreover, seroprevalence is low in Australian women (11 per 100018), and no cost-effectiveness studies have been undertaken.

The rate of vertical transmission of HCV from mother to child is about 6%,19 but the timing and mode of vertical transmission and the best management strategy to reduce it are currently unclear. The role of caesarean section in reducing the rate of vertical transmission is uncertain, with studies producing conflicting results.20,21 Our results reflect obstetricians’ caution in this respect, with only a small proportion always offering elective caesarean section to women infected with HCV.

Similarly, our respondents were cautious about performing fetal scalp monitoring. Although it has been reported that such interventions may have the potential to increase vertical transmission of HCV,22 this has never been adequately assessed in prospective, randomised controlled trials. Nevertheless, it may be prudent to avoid fetal scalp monitoring if there are other, equally effective non-invasive means of monitoring the neonate.

As with HBV, a substantial proportion of obstetricians are giving incorrect advice about the risk of transmission of HCV through breastfeeding. HCV RNA has been found in breastmilk by some investigators23 but not by others.24-26 Despite the theoretical risk of transmission, there is no evidence that breastfeeding increases the risk of transmission of HCV from mother to child.26,27

HIV. Despite RANZCOG guidelines recommending universal screening for HIV, only about half of the respondents said they would always screen for HIV. Obstetricians may have a number of concerns about routinely offering HIV screening: the cost to the healthcare system of screening for an infection with low seroprevalence in Australia, the management issue of false-positive results and potential psychological harm this may cause, and the time constraints that may limit appropriate pre- and post-test counselling. A cost–benefit analysis of antenatal HIV screening in Australia (to our knowledge, the only one of its kind) used a model to predict the cost per life-year gained at many prevalences and then assumed a life-year gained was worth $39 000. Based on this figure, the minimum prevalence at which universal antenatal screening for HIV would be cost-effective is 0.004372% (Dr Nick Graves, Senior Research Fellow in Health Economics, School of Public Health, Queensland University of Technology, personal communication).

Transmission of HIV-1 infection from mother to child usually occurs around the time of delivery, largely intrapartum.28 Although there is clear evidence that elective caesarean section is associated with reduced perinatal transmission of HIV,9,29 only 36% of respondents said they would always recommend an elective caesarean section to a pregnant woman infected with HIV. Some obstetricians may not always offer caesarean section because they are uncertain whether caesarean delivery offers any additional benefit in reducing transmission in women who are receiving antiretroviral therapy and have undetectable viral loads. However, transmission has been reported in women with viral loads of less than 1000 copies/mL.30

Longer duration of ruptured membranes has been consistently associated with increased vertical transmission of HIV in women not receiving antiretroviral therapy.31-33 However, in the era of combination antiretroviral therapy and low maternal viral load, the additional risk of ruptured membranes and duration required to increase transmission risk is unknown. This may explain why many obstetricians would not always avoid rupture of membranes in a woman infected with HIV.

Study limitations. One of the limitations of our study was the fact that, because of privacy restrictions, we could not obtain demographic information about non-responders. Although this limits our ability to conclude that the responders are representative of obstetricians as a whole, we feel this is to some extent counteracted by the relatively high response rate and the fact that every state and territory in Australia was represented.

A second limitation of our study was that we did not directly ask obstetricians whether they had managed women with a known blood-borne virus infection. It would have been useful to correlate whether the obstetricians whose responses were consistent with current evidence-based guidelines were in fact those who had had experience in managing such women during pregnancy.

As a follow-up to our study, educational material has been provided to all obstetricians by way of publications in their professional journal.34 In addition, an education pamphlet has been developed and forwarded to all obstetricians along with feedback on the key questionnaire results. A second survey will be undertaken in early 2004 to assess the impact of this education process.