Incidence of GLP‐1 receptor agonist use by women of reproductive age attending general practices in Australia, 2011–2022: a retrospective open cohort study

Objective To examine longitudinal changes in the initial prescribing of glucagon‐like peptide 1 (GLP‐1) receptor agonists for women of reproductive age in Australia; to determine whether contraception recommendations are being followed; and to estimate the frequency of pregnancy among women using GLP‐1 receptor agonists. Study design Retrospective open cohort study; analysis of MedicineInsight general practice data. Setting, participants Women aged 18–49 years who visited participating general practices three or more times during the study period (1 January 2011 – 31 July 2022). Main outcome measures Age‐standardised incidence of initial GLP‐1 receptor agonist prescribing, by year and type 2 diabetes status; proportion of women using highly effective contraception at the time of GLP‐1 receptor agonist initiation (contraception overlap); age‐standardised incidence of pregnancy within six months of the first prescribing of GLP‐1 receptor agonists. Results Of 1 635 684 women aged 18–49 years, 18 010 (1.1%) were first prescribed GLP‐1 receptor agonists during 2011–2022, of whom 3739 (20.8%) had type 2 diabetes. The age‐standardised incidence of GLP‐1 receptor agonist prescribing for women with type 2 diabetes increased from 13.0 per 1000 women in 2011 to 88.5 per 1000 women in 2022; for women without type 2 diabetes, it increased from 0 to 14.9 per 1000 women. Of the 6293 women first prescribed GLP‐1 receptor agonists during 2022, 6954 (90.5%) did not have type 2 diabetes. Contraception overlap with first prescribing of GLP‐1 receptor agonists was determined for 3825 women (21.2%). Pregnancies within six months of GLP‐1 receptor agonist prescribing were documented for 232 of 10 781 women for whom at least six months of follow‐up data were available. Conclusions The prescribing of GLP‐1 receptor agonists for women of reproductive age is increasing in Australia, and most prescriptions are for women not diagnosed with type 2 diabetes. Fewer than one in four women are using contraception at the time of treatment initiation, and a considerable number are pregnant within six months of the initial prescribing of GLP‐1 receptor agonists. Further evidence and guidelines are needed to support the safe and effective use of GLP‐1 receptor agonists by women of reproductive age.