Number of events, follow up, and incidence of first hospital admission for asthma in relation to mode of delivery and neonatal respiratory morbidity
| Mode of delivery and neonatal characteristics | n | Number of asthma admissions | Total years of follow up | Expected asthma admissions | Crude HR (95% CI) | p | †Adjusted HR (95% CI) | p | |
|---|---|---|---|---|---|---|---|---|---|
| *Reference category. | |||||||||
| †Hazards were non-proportional for hospital, maternal age, birth weight for gestation, parity, and smoking. Therefore, multivariate analysis was stratified by these variables and adjusted for induction, maternal height, week of gestation, male sex, Apgar, deprivation category, and maternal asthma. Goodness of fit: p = 0.4. | |||||||||
| RDS, denotes respiratory distress syndrome; TTN, transient tachypnoea of the newborn. | |||||||||
| Vaginal birth | No TTN/RDS* | 146 404 | 3171 | 1 002 961 | 3264 | (1.0) | (1.0) | ||
| With TTN/RDS | 1366 | 44 | 9218 | 30 | 1.5 (1.1 to 2.0) | 0.007 | 1.4 (1.0 to 1.8) | 0.04 | |
| All caesarean | No TTN/RDS | 24 505 | 601 | 166 397 | 544 | 1.1 (1.0 to 1.2) | 0.004 | 1.1 (1.0 to 1.2) | 0.006 |
| sections | With TTN/RDS | 864 | 40 | 5767 | 19 | 2.2 (1.6 to 3.0) | <0.001 | 2.2 (1.6 to 3.0) | <0.001 |
| Emergency | No TTN/RDS* | 14718 | 357 | 99 848 | 326 | 1.1 (1.0 to 1.3) | 0.034 | 1.1 (1.0 to 1.3) | 0.04 |
| caesarean section | With TTN/RDS | 411 | 18 | 2775 | 9 | 2.1 (1.3 to 3.3) | 0.002 | 2.2 (1.4 to 3.6) | 0.001 |
| Elective | No TTN/RDS | 9787 | 244 | 66 549 | 217 | 1.2 (1.0 to 1.3) | 0.031 | 1.1 (1.0 to 1.3) | 0.06 |
| caesarean section | With TTN/RDS | 453 | 22 | 2992 | 10 | 2.3 (1.5 to 3.5) | <0.001 | 2.2 (1.4 to 3.4) | <0.001 |