Stage III Chorioamnionitis is Associated with Reduced Risk of Severe Retinopathy of Prematurity.

OBJECTIVE: To identify whether histologically confirmed chorioamnionitis (hCAM) is associated with development of retinopathy of prematurity (ROP). STUDY DESIGN: We retrospectively analyzed 2 different cohorts. Cohort 1 was the national database of newborns in Japan born at ≤1500g or <32 weeks' gestation (January 2003 through April 2021, n = 38 013). Cohort 2 was babies born at <1500g from a single institution in Tsuchiura, Japan, (April 2015 through March 2018, n = 118). RESULTS: For Cohort1, after adjusting for potential confounders, stage III CAM (n = 5554) was associated with lower odds of severe ROP (stage ≥3 or required peripheral retinal ablation) by 14% (OR: 0.86; 95% CI: 0.78-0.94]. CAM of stage I (n = 3277) and II (n = 4319) was not associated with the risk of ROP. For Cohort 2, the odds of severe ROP were significantly reduced in moderate to severe hCAM groups (stage II, OR: 0.06, 95% CI: 0.05-0.82; stage III, OR: 0.10, 95% CI: 0.01-0.84). Neonates with funisitis, comorbidity of hCAM, and a finding of fetal inflammatory response had lower odds of severe ROP (OR: 0.11; 95% CI: 0.01-0.93). CONCLUSIONS: After adjusting for confounders, severe hCAM with fetal inflammatory response was associated with reduced risk of ROP.