Recommendations from the Canadian 2024 HIV in Pregnancy Update Relevant to Australia and Aotearoa New Zealand

30 years ago, the rate of perinatal transmission of human immunodeficiency virus (HIV) was around 30%. The introduction of anti-retroviral therapy (ART) during pregnancy in the 1990s transformed management reducing perinatal transmission to <1%.  Globally, this is under threat, with recent funding cuts to major aid organisations providing HIV care. For Australia and Aotearoa New Zealand where cases are few, but high stakes, the Society of Obstetricians and Gynaecologists of Canada (SOGC) updated guideline on HIV care in pregnancy provides important, evidence-based considerations for management that are applicable to our context with many parallels in terms of at-risk groups and available resources.

Why it Matters Locally and What Guidance is Available

Australia and Aotearoa New Zealand record only a handful of HIV-affected pregnancies each year, with no recent documented perinatal transmissions. The Australasian Society for Infectious Diseases (ASID) guidelines provide brief treatment algorithms for use in acute scenarios which are drawn from US and British guidelines and provide a useful snapshot of treatment.¹

The Canadian Society of Obstetricians and Gynaecologists’ 2024 guideline provides a comprehensive, evidence-based roadmap.² Its recommendations, while tailored to a Canadian context, resonate strongly for Australia and Aotearoa New Zealand, where equity of health care for migrant, First Nations, and remote populations remain central.

Some essential knowledge for pregnancy care providers, key points, and brief controversies drawn from the SOGC and ASID guidance are presented below:

Essential Facts for Clinicians and Public Regarding HIV Care in Pregnancy

1. U=U: Undetectable equals untransmissible. This is true for conception, pregnancy, and intrapartum care, and is important to provide reassurance and reduce stigma for patients.
2. 100% adherence and absorption of combined ART results in undetectable viral loads.Once established on effective ART, patients will maintain undetectable viral loads. Resistance only occurs in the presence of detectable viral loads resulting from lack of adherence or disruption in medication absorption.
3. ART is safe during pre-pregnancy, pregnancy, and post-partum for both mother and baby. This should be reinforced by providers when patients are planning pregnancy, or encounter unplanned pregnancy, to prevent treatment interruption.
4. Vaginal delivery is safe and does not increase the risk of perinatal transmission in the setting of an undetectable viral load and optimal adherence to combined ART.

Key Principles of Care in Pregnancy to Prevent Perinatal Transmission of HIV

Universal Screening

• First trimester HIV testing remains routine, with repeat testing in each trimester for women at high risk (e.g. sero-discordant couples, ongoing injecting drug use, or migration from endemic regions).
• Rapid testing in labour provides a last opportunity to identify infection and initiate emergency prophylaxis for patients not engaged in care.

Antiretroviral Therapy

• Indicated for all pregnant women living with HIV, regardless of CD4 count or viral load.
• Preferred regimens: a dual nucleoside reverse transcriptase inhibitor backbone (tenofovir + lamivudine/emtricitabine) plus an integrase inhibitor (dolutegravir or raltegravir).
• Continue established regimens even if containing older drugs such as efavirenz and nevirapine.
• Manage nausea early and aggressively as this is a major barrier to absorption and adherence, resulting in detectable viral loads with potential for transmission and resistance.
• Drug interactions matter: iron, calcium, and antacids can reduce integrase inhibitor absorption. Dose spacing is essential.

Monitoring

• Viral load every 4-12 weeks with a key check at 36 weeks.
• HIV infection is a risk factor for preterm birth with multifactorial causes, which should be considered when determining fetal monitoring, antenatal care, and delivery planning.
• Obstetric ultrasounds as per routine guidelines in Australia and Aotearoa New Zealand, with third trimester scan for fetal growth.

Delivery Planning

• In all scenarios where vaginal delivery is anticipated, avoid invasive monitoring (scalp electrodes, fetal blood sampling) and minimise duration of rupture of membranes where possible.
• Various thresholds for mode of delivery decisions based on viral load exist. The SOGC guideline suggests the following:
  • Undetectable (<50 copies/mL at term): Vaginal birth is safe; caesarean reserved for obstetric indications.
  • High viral load (≥400 copies/mL or unknown): Planned caesarean at 38 weeks with intrapartum zidovudine.
  • Intermediate (50–399 copies/mL): Case-by-case multidisciplinary planning. IV zidovudine.
• Presentation in labour, known HIV diagnosis not on treatment: Offer caesarean section if not in active labour with intact membranes, commence IV zidovudine, consider rapid start ART with dual NRTI (commonly used in PEP regimens) and an INSTI, such as raltegravir, for rapid viral suppression. Urgent paediatric infectious disease input.

Current Controversies

Does U=U include lactation and breast feeding?

The postpartum period is vulnerable for ART adherence. ASID and SOGC recommend formula feeding but emphasise shared decision-making, supporting exclusive breastfeeding with added maternal monitoring and infant prophylaxis if chosen.

If undetectable with optimal control, is IV zidovudine required in labour?

ASID guidelines suggest if viral load is undetectable with reliable adherence and recent confirmation, IV zidovudine is not required, though the SOGC advises giving it if there is uncertainty or complex risk factors.

Are long acting (depot) antiretroviral treatments safe in pregnancy?

There remains a lack of safety data in pregnancy for these newer medications, but they provide an exciting future treatment and prevention strategy once more information is available.

Global Issues

In 2024 there were 40.8 million people globally living with HIV and 53% were women or girls. 31.6 million were accessing ART and only 84% of pregnant women living with HIV had access to ART to prevent perinatal transmission.³ Unfortunately, this has recently come under threat, with foreign assistance freezes announced by the US government in January 2025. Approximately 70% of all foreign aid funding for HIV comes from the US government through the President’s Emergency Plan for AIDS Relief (PEPFAR) and other United States Agency for International Development (USAID) initiatives. A recent Lancet HIV modelling study estimates the proposed donor cuts by the five major countries responsible for the majority of international HIV funding will result in substantive and potentially abrupt lack of access to effective antiretroviral therapy, which could result in 4.4-10.8 million additional HIV infections by 2030, including up to 880,000 additional infections in children due to the lack of ART for pregnant mothers.⁴

This has highlighted the precarious nature of health systems’ dependency on humanitarian aid, and is hoped to drive innovation in non-reliance on foreign aid, but any rapid withdrawal threatens to undo decades of work in preventing perinatal transmission.

Although these immediate impacts will predominantly be felt in sub-Saharan Africa, with immigration/refugee intake, countries such as Canada, Australia and Aotearoa New Zealand will need to be prepared for the consequences of escalating global epidemics on systems that may not have the recency of knowledge in previously managing rare diseases in our populations.

Conclusion

The Canadian SOGC 2024 guideline provides a practical, evidence-based framework for perinatal HIV care. Its lessons are highly relevant for Australia and Aotearoa New Zealand, where rare cases demand precision, equity, and global solidarity.

HIV care in pregnancy is a public health success story—yet one easily undone. To prevent the return of perinatal transmission, we must preserve the lost ART of prevention: universal screening, timely ART, neonatal prophylaxis, and stigma-free, woman-centred care.