Prescribing Patterns of Antiretroviral Treatments During Pregnancy for Women Living With HIV in Canada 2004–2020

A Surveillance Study

Sabrina Carvalho; Terry Lee; Karen J Tulloch; Laura J Sauve; Lindy Samson; Jason C Brophy; Ari Bitnun; Joel Singer; Deborah Money; Fatima Kakkar; Isabelle Boucoiran

Disclosures

HIV Medicine. 2023;24(2):130-138.

Abstract and Introduction

Abstract

Background: While treatment guidelines for HIV in adults have evolved rapidly with the advent of new antiretroviral (ARV) treatment, those for the prevention of vertical HIV transmission in pregnancy have evolved more slowly due to safety and efficacy concerns. Here we describe Canadian prescribing patterns for ARV treatments during pregnancy and compare them to perinatal HIV prescribing guidelines of the United States Department of Health and Human Services (HHS), that are commonly used in Canada and include recommendations for newly commercialized therapies.

Methods: The Canadian Perinatal HIV Surveillance Program (CPHSP) captures annual medical data on mothers living with HIV and their infants from 23 sites across Canada. Women from this cohort who received an ARV treatment during pregnancy and who gave birth between 2004 and 2020 were included in the study. ARV treatments were designated as 'preferred/alternative' as per HHS HIV perinatal guidelines, or 'other than preferred/alternative'.

Results: We identified 3673 pregnancies from 2720 women. The proportion of women that conceived while on ARV treatment increased from 29% in 2003 to 90% in 2020. Other than preferred/alternative ARV treatments were received in 1112 (30%) of pregnancies and this was significantly associated with having initiated ARV treatment before conception.

Conclusion: In Canada during the study period, a high number of women were prescribed an other than preferred/alternative ARV treatment during pregnancy. Further optimization of ARV treatment in women of childbearing age living with HIV is warranted.

Introduction

In Canada during the last decade, the rate of vertical HIV transmission has decreased dramatically from 15% to 40% in antiretroviral (ARV)-naïve women^[1] to less than 1% for those receiving maternal ARV treatment with infant prophylaxis at birth.^[2] Several North American guidelines for ARV treatment and care of pregnant women living with HIV exist, including Canadian national guidelines,^[3,4] provincial guidelines,^[5,6] and the guidelines of the United States Department of Health and Human Services (HHS) Task Force. The HHS HIV perinatal guidelines are the most commonly used in Canada because they are updated annually and include recommendations on newly commercialized treatments.^[7] Since 2004, each of these guidelines recommends that all pregnant women living with HIV receive ARV treatment.^[3–7]

In North America there are currently 24 ARV drugs approved for treating HIV, more than half of which have become available since 2015.^[8] While new ARV drugs have been systematically and comprehensively incorporated into some HIV treatment guidelines for adults in general, this has not been the case for guidelines for pregnant women specifically, mainly because of insufficient safety and efficacy data in this population.^[7]

The primary objective of this study was to describe Canadian prescribing practices regarding ARV treatment of HIV in pregnancy in comparison to HHS perinatal guideline recommendations available at the time. The secondary objective was to identify factors that could explain reasons for prescribing other than preferred/alternative ARV treatments.

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Abstract and Introduction
Methods
Results
Discussion
Conclusions
References

Table 1. Maternal characteristics during pregnancy according to the type of antiretroviral treatment ^a
Characteristic	Preferred/alternative (n = 2546) (69.6%)	Other than preferred/alternative (n = 1112) (30.4%)	Missing (n = 15)	P value ^b
Geographical location^c				<0.001
Ontario	840 (33.0)	441 (39.7)
Quebec	566 (22.2)	180 (16.2)
British Columbia	316 (12.4)	87 (7.8)
Alberta	331 (13.0)	245 (22.0)
Saskatchewan	286 (11.2)	117 (10.5)
Manitoba	197 (7.7)	31 (2.8)
Other	10 (0.4)	11 (1.0)
Race/ethnicity			40	<0.001
Black	1304 (51.8)	668 (60.6)
White	464 (18.4)	188 (17.1)
Indigenous	549 (21.8)	195 (17.7)
Other	199 (7.9)	51 (4.6)
Timing of HIV diagnosis and ARV treatment initiation			328	<0.001
Before conception for both	1230 (53.7)	795 (76.5)
Diagnosed before conception initiation of ARV treatment during pregnancy	700 (30.6)	186 (17.9)
Both during pregnancy	361 (15.8)	58 (5.6)
Viral load closest to delivery			406	0.186
Undetectable	1905 (87.6)	959 (89.0)
Detectable	269 (12.4)	119 (11.0)
HIV vertical transmission	14 (0.6)	7 (0.6)	75	0.915
Mother's mode of HIV acquisition			376	0.003
Perinatal	39 (1.7)	35 (3.6)
Other	2276 (98.3)	932 (96.4)
Year of conception				<0.001
2003–2006	572 (22.5)	50 (4.5)
2007–2009	425 (16.7)	190 (17.1)
2010–2013	633 (24.9)	265 (23.8)
2014–2020	916 (36.0)	607 (54.6)

Abbreviation: ARV, antiretroviral.
^aAccording to Human Health Services HIV perinatal guidelines definitions, number (%).
^b _{P values were based on mixed effects logistic regression which accounted for correlations between multiple pregnancies for the same woman.}
^cOntario (n = 1285), Quebec (n = 749), British Columbia (n = 405), Alberta (n = 576), Saskatchewan (n = 409) and Manitoba (n = 228). The category 'Other' includes women from New Brunswick (n = 3), Nova Scotia (n = 15) and Yukon (n = 3).

Table 2. Associations between sociodemographic and clinical characteristics, and prescriptions for antiretroviral treatments other than preferred/alternative in pregnancy ^a
Characteristic	Unadjusted OR [95% CI](n = 3658–3282)	P value	Adjusted OR[95% CI]^b (n = 2990)	P value
Geographical location^c
Ontario	1		1
Quebec	0.50 [0.38–0.67]	<0.001	0.50 [0.37–0.69]	<0.001
British Columbia	0.44 [0.30–0.62]	<0.001	0.52 [0.34–0.79]	0.003
Alberta	1.51 [1.14–2.00]	0.004	1.60 [1.09–2.35]	0.017
Saskatchewan	0.71 [0.52–0.99]	0.044	0.94 [0.56–1.56]	0.799
Manitoba	0.22 [0.14–0.37]	<0.001	0.19 [0.10–0.34]	<0.001
Other	2.69 [0.83–8.67]	0.098	2.16 [0.19–24.27]	0.531
Race/ethnicity
Black	1		1
White	0.73 [0.56–0.96]	0.024	0.96 [0.71–1.30]	0.794
Indigenous	0.61 [0.46–0.79]	<0.001	0.86 [0.56–1.31]	0.474
Other	0.42 [0.27–0.65]	<0.001	0.52 [0.32–0.85]	0.008
Timing of HIV diagnosis and ARV treatment initiation
Both during pregnancy	1		1
Before conception for both	5.95 [4.05–8.75]	<0.001	4.72 [3.07–7.27]	<0.001
Diagnosed before conception and initiation of ARV treatment during pregnancy	1.86 [1.25–2.77]	0.002	1.84 [1.18–2.89]	0.008
Mother's mode of HIV acquisition
Other	1		1
Perinatal	2.82 [1.43–5.54]	0.003	1.68 [0.83–3.41]	0.151
Year of conception
2003–2006	1		1
2007–2009	7.70 [4.98–11.89]	<0.001	7.08 [4.34–11.53]	<0.001
2010–2013	7.46 [4.89–11.38]	<0.001	5.19 [3.27–8.23]	<0.001
2014–2020	13.52 [8.86–20.64]	<0.001	8.50 [5.35–13.52]	<0.001

Abbreviations: ARV, antiretroviral; CI, confidence interval; OR, odds ratio.
^aAccording to Human Health Services HIV perinatal guidelines definitions.
^bOnly pregnancies with complete data (all variables) were considered in the multivariable analysis.
^cOntario (n = 1285), Quebec (n = 749), British Columbia (n = 405), Alberta (n = 576), Saskatchewan (n = 409) and Manitoba (n = 228). The category 'Other' includes women from New Brunswick (n = 3), Nova Scotia (n = 15) and Yukon (n = 3).