P177 Cystic fibrosis (CF)-related complications and outcomes of women during pregnancy and post-partum in elexacaftor/tezacaftor/ivacaftor (ETI)-era

A significant rise in pregnancies in women with CF (wwCF) has been noted since ETI availability. Maternal CF-outcomes are of interest in this new therapeutic era. Single-centre records review of wwCF who completed pregnancies Sept 2020-Nov 2022, excluding 3 on ivacaftor. Pregnancies were grouped as ‘ETI’ (taken for all or part-pregnancy) or ‘No-ETI’ (never or ceased at conception). 29 women completed 31 pregnancies (32 live births, 1 twin pregnancy), with 20 ‘ETI’ vs 11 ‘No-ETI’ pregnancies. At baseline, 80% were Pseudomonas aeruginosa colonised in each group, with minimal difference in nutritional status (BMI (Kg/m2) ETI: median (IQR) = 22.65 (19.8, 24.6); No-ETI: 22.3 (19.6, 21.9) p = 0.03). 5 wwCF had CF-diabetes (all ETI). Lung function was lower in wwCF who continued ETI (mean (SD) FEV1 = 2.03 L (±0.62), ppFEV1 = 69.7% (±23.3); No-ETI: FEV1 = 2.45 L (±0.64), ppFEV1 = 75.4% (±21.3) p = 00.8, p = 0.5). 7 women ceased ETI when pregnant, of whom 3(43%) restarted by 3rd trimester due to significant spirometric decline (30% FEV1 decline, n = 2) or pulmonary exacerbation (PEx, n = 1) requiring hospitalisation, with restoration of baseline values. A trend of fewer PEx was observed in wwCF continuing ETI (mdn (IQR) PEx = 1 (0,2) vs No-ETI: 3(0,3) p = 0.26). There was no difference in antenatal weight gain (ETI: mean (SD) Kg = +9.6 ± 4.6; No-ETI: +9.4 ± 4.2, p = 0.89) and spirometry within 4 weeks pre-partum showed minimal decline from baseline (ETI: ppFEV1 mean (SD) = – 0.09% (±0.33); No-ETI: –0.06% (±0.32), p = 0.24) or at 6-months postpartum (ETI: ppFEV1 mdn (IQR) = 0 (–0.1, 0.1); No-ETI: –0.03% (–0.19, 0.16), p = 1). Regarding ETI-use, whilst CF-outcomes show minimal variation with no significant decline, 43% of wwCF who discontinue suffer significant pulmonary destabilisation which is reversed on recommencement. Pre-conception counselling of potential pulmonary-protection conferred by ETI is warranted for wwCFas those who continue ETI may experience fewer antenatal CF-complications.