Characteristics and outcomes of infants born at <32 weeks’ gestational age in England and Wales from 2010 to 2017 with and without a patent ductus arteriosus (PDA)
| Infant characteristics | With PDA | Without PDA | P value for difference |
| n (%) | 16 440 (28.3) | 41 668 (71.7) | |
| Females, n (%) | 7691 (46.8) | 18 905 (45.4) | 0.002 |
| Gestational age at birth (weeks), median (IQR) | 27 (25–28) | 30 (28–31) | <0.001 |
| Birth weight (in g), mean (SD) | 969 (312) | 1310 (360) | <0.001 |
| Birth weight z-score, mean (SD) | −0.15 (0.94) | −0.02 (0.98) | <0.001 |
| Length of stay (days), median (IQR) | 80 (56–106) | 42 (31–59) | <0.001 |
| Adverse outcomes | With PDA | Without PDA | Adjusted OR (95% CI)* |
| Bronchopulmonary dysplasia, n (%) | 5467 (33.3) | 3071 (7.4) | 2.95 (2.80 to 3.12)† |
| Necrotising enterocolitis, n (%) | 1181 (7.2) | 760 (1.8) | 1.96 (1.77 to 2.18)† |
| Late onset sepsis, n (%) | 10 171 (61.9) | 9836 (23.6) | 2.72 (2.61 to 2.85)† |
| Death before discharge, n (%) | 1904 (11.6) | 3477 (8.3) | 0.30 (0.27 to 0.32)† |
*Adjusted for sex, gestational age and birth weight z-score <-2SD.
† P<0.05 with Bonferroni correction.