Prescribing of glucagon-like peptide-1 receptor agonists to Australian women of reproductive age increased between 2011 and 2022, often in patients without type 2 diabetes, according to a retrospective cohort study.
Among nearly 1.6 million women aged 18 to 49 years, 18,010 patients (1%) were first prescribed a glucagon-like peptide-1 receptor agonist (GLP-1 RA) during the study period, 21% of whom had type 2 diabetes. The incidence among patients with diabetes rose from 13 per 1,000 in 2011 to 89 per 1,000 in 2022. In patients without diabetes, the rate rose from 0 to 15 per 1,000. In 2022, 6,954 patients began therapy, and 6,293 (91%) did not have diabetes.
Pregnancy within six months of initiation occurred in 232 of 10,781 women with adequate follow-up (2%), with the highest rates in women aged 18 to 29 years with diabetes (4%) and those aged 30 to 34 years without diabetes (6%). Women with polycystic ovary syndrome were twice as likely to conceive as others (adjusted relative risk, 2.04).
Only 21% of patients were using contraception at initiation, and long-acting reversible contraception coverage was lower than national averages. Contraception use was associated with reduced pregnancy rates (1.7% vs 2.3%).
Patients with diabetes were older at initiation (median age 43 years vs 38 years) and had higher body mass index (39 kg/m² vs. 35 kg/m²). Most prescriptions were issued by general practitioners. Among patients without diabetes, semaglutide and liraglutide were most common. Among patients with diabetes, exenatide and semaglutide were most frequently prescribed.
Eligible patients were women aged 18 to 49 years who had at least three visits to participating practices. Outcomes included incidence of first GLP-1 RA prescriptions, contraception use at initiation, and pregnancy within six months of initiation.
The analysis covered about 8% of Australian general practices. Dispensing records were unavailable, so actual medication use could not be confirmed. Contraception duration was estimated. Pregnancies were identified only through general-practice records, and pregnancy outcomes were not captured. Some duplication of patients across practices was possible.
“The reasons for the low coverage level could be related to limited awareness of the risks associated with GLP-1 receptor agonist use during pregnancy, or perceptions of reduced fertility in women with type 2 diabetes, polycystic ovary syndrome, or obesity,” wrote lead author Kailash Thapaliya, PhD, Flinders University and the South Australian Health and Medical Research Institute, and colleagues. "However, as modest reductions in weight can improve fertility, 30 the risk of unintended pregnancy is significant if effective contraception is not used."
The researchers reported that further evidence and guidance are needed to support safe prescribing in this population.
The authors reported no conflicts of interest.
Source: The Medical Journal of Australia