Longer life expectancy and improved health status due to availability of combination antiretroviral therapy  has contributed to an increased rate of pregnancy among women living with HIV (WLWH) . A retrospective analysis involving 1165 Canadian WLWH reported that 61% of pregnancies were unintended ; a value that exceeds the Canadian average of up to 40% . Unintended pregnancies are associated with negative outcomes such as delayed antenatal care and low birth weight . These risks are elevated for WLWH as there is potential for vertical HIV transmission . Whilst the primary goal of contraception is often pregnancy prevention , contraceptive choice is influenced by life circumstances, patient-centered goals and factors such as cost, religious beliefs, side effects, and protection from sexually transmitted infections [6, 7]. Concurrently, healthcare provider (HCP) consideration of patient comorbidities, drug interactions, and behavioral factors also influence contraceptive choice . Access to a full range of contraceptive options supports a woman’s reproductive rights . Furthermore, preventing unintended pregnancies decreases maternal and infant morbidity and mortality risks  and the probability of vertical HIV transmission . Thus, safe contraceptive options and choice are imperative for WLWH.
The World Health Organization (WHO) guidelines state that WLWH should be offered a full range of contraceptive options ; however previous studies assessing contraceptive choice in WLWH have shown that the range of methods used in Canada is limited, particularly related to hormone-based contraceptives use [11, 12]. Approximately 9–21% of sexually active WLWH in Canada use hormonal contraceptives (injectable depo-medroxyprogesterone, combined hormonal contraceptives [CHC] by vaginal ring, patch or oral delivery , or levonorgestrel-releasing intrauterine device [LNG-IUD]) [11, 12], a rate less than half of that used by the general Canadian population (44%) . Specific antiretroviral medications (ARVs), other drugs, certain medical comorbidities, and smoking when ≥ 35 years of age are contraindications to using CHC [8, 10, 14, 15]. Assessing patient choice and associated medical factors is an important step toward understanding prescribing practices and contraceptive methods used among WLWH.
Several commonly used ARVs reduce the efficacy of CHC [8, 10, 14, 15]. These ARVs may induce the liver CYP450 3A4 system that metabolizes estrogen, thus accelerating its clearance . Use of efavirenz, darunavir, or combined use of lopinavir/ritonavir in tandem with CHC is contraindicated, while elvitegravir or atazanavir require a higher dose ethinyl estradiol-containing CHC to be effective [16,17,18,19,20]. ARV treatment guidelines advise prescribers to either avoid simultaneous CHC use, or to provide a higher dose ethinyl estradiol-containing CHC when also taking interacting ARVs . Other contraindications include: anticonvulsants, rifamycins (such as rifampin), and smoking in women ≥ 35 years old [8, 10]. World Health Organization (WHO) guidelines state that use of CHC is contraindicated in the presence of any of the following comorbidities: hypertension, deep vein thrombosis/pulmonary embolism, diabetes with retinopathy, neuropathy, or nephropathy, diabetes duration > 20 years, migraine with aura, liver tumour, myocardial infarction, stroke, severe cirrhosis/liver failure, active cancer or history of breast cancer . If the prevalence of these CHC-related contraindications is greater among WLWH, this may influence contraceptive prescribing practices, and therefore partially explain the low rate of hormonal contraceptive use found in previous studies.
Previous cohort studies assessing factors associated with contraceptive use in Canada looked at psychological, socio-behavioral, demographic, sexual, and reproductive characteristics [11, 12]. However, little is known about contraceptive choice in relation to medical comorbidities, drug contraindications, and smoking. We assessed and compared the prevalence of contraceptive choice among WLWH and controls (women not living with HIV) in the Children and Women: Antiretrovirals and Markers of Aging (CARMA) cohort. We then examined the relationship of medical comorbidities, drug contraindications, and smoking with participant self-reported contraceptive use. For the purpose of this paper, whenever we use the term “women”, we are referring to “cis-women”.