AbstractObjectives Historically, pregnancies in females with CF (FwCF) were considered high-risk1, with a high prevalence of gestational diabetes mellitus (GDM)1–3. Widespread availability of CFTRm has led to significantly increased pregnancy rates. This study reviewed pre-conception characteristics of FwCF who develop GDM to better inform FwCF and clinicians about individualised risk of GDM and contribute to the evidence base for personalised pre-conception counselling. Methods Retrospective review of clinically collected data from FwCF who completed pregnancies between September 2020 - November 2025 as part of a quality improvement evaluation for a CF-Reproductive and Maternal Health Service. Females with CF-related diabetes (CFRD) or pre-pregnancy dysglycaemia were excluded. CF characteristics were compared according to incidence and timing of GDM diagnosis. Results 77 pregnancies were completed by 60 FwCF. 19/77 (25%) FwCF with CFRD were excluded from analysis, and one removed due to insufficient data. 27/57 (47%) pregnancies (45 FwCF) were complicated by GDM. 48% of GDM diagnoses were made at an early oral glucose tolerance test (OGTT). FwCF developing GDM had a higher BMI (GDM: 23.7+0.8kg/m2 (mean+SEM); No GDM: 21.4+0.5kg/m2, pConclusion Despite improved CF-health status, elevated GDM risk persists in FwCF relative to the general population. Recognition of value and indication for two OGTTS for GDM screening is evident as almost 50% cases were detected early. Further research into how CFRD and GDM impacts maternal/fetal outcomes in FwCF is warranted.
Downes et al. (Sun,) studied this question.