(641) The trend in incidence of cystic fibrosis and severe maternal morbidity during delivery admissions

The prevalence of severe maternal morbidity (SMM) associated with delivery among people with cystic fibrosis (pwCF) has not yet been assessed. We suspect the wider advent of cystic fibrosis transmembrance conductance (CFTR) modulators since 2015 has affected the outcome of pregnant pwCF. We aim to evaluate the trend of cystic fibrosis (CF) during delivery admissions and its association with severe maternal morbidity.

Study Design:

Using previously establised method we identified labor and delivery admissions in the Nationwide Inpatient Sample (NIS) from the year 2009 to 2019 (2015 was excluded since it was a transitional year for widespread use of CFTR modulators). Cases of pregnant pwCF were isolated using ICD-9 codes (277.00, 277.01, 277.02, 277.03 and 277.09) and ICD-10 code (E84.x). The trend in incidence of pregnancy among pwCF and its associated SMM across the study year were evaluated. Fisher's exact test was used to compare the incidence of SMM among pregnant pwCF and without during the study period. This test was also used to compare the rate of SMM among pregnant pwCF before and after 2015.

Results: A total of 7,232,126 delivery admissions were identified in NIS database from 2009-2019 (excluding 2015). We identified a total of  646 delivery among pwCF.  This accounts for ~20% of labor and delivery admissions. The trend in incidence of pregnancy among pwCF was shown in figure 1. The trend of SMM among pregnant pwCF and without were shown in figure 2. Pregnant pwCF are more likely to have SMM (OR: 5.6, 95% CI 3.5 - 8.6, p< 0.001) through the study period. The rate of SMM among pregnant pwCF was similar before and after 2015 (3.1 vs. 3.9%, p:0.6)

Conclusion: We presented the most updated population data on the trend in pregnancy among pwCF in the United States. We saw an increase of pregnancy among pwCF within the last decade. While not statistically significant, we saw a trend in decrease in SMM among pregnant pwCF after wider availability of CFTR modulators in 2015. While comparatively safer than previously reported, cystic fibrosis remains to be a significance risk factor for SMM.