Table 2.
Relationship between the time to delivery after the first dose of betamethasone and Neonatal Morbidities
| Neonatal Morbidity | Time to delivery after 1st dose of betamethasone | Unadjusted Odds ratio (or Coefficient) for Time to delivery ≥ 24 hours (95% CI) | Adjusted* Odds ratio (or Coefficient) for Time to delivery ≥24 hours (95% CI) | P value† | ||
|---|---|---|---|---|---|---|
| ≤6 hrs N= 183 |
7–23 hrs N = 55 |
≥24 hrs N = 429 |
||||
| Severe IVH‡ (%) | 35 | 19 | 9 | 0.18 (0.12, 0.29) | 0.13 (0.07, 0.27) | <0.0001 |
| Intubated-Mechanical Ventilation at 24h (%) | 88 | 67 | 76 | 0.45 (0.27, 0.73) | 0.47 (0.23, 0.98) | 0.043 |
| Respiratory Severity Score at 24h (mean ± SD)§ | 2.7±2.3 | 1.6 ± 0.6 | 2.1 ± 1.4 | −0.57 (−0.98, −0.26) | −0.42 (−0.72, − 0.01) | 0.014 |
| Death (%) | 35 | 25 | 17 | 0.39 (0.32, 1.25) | 0.25 (0.13, 0.47) | <0.0001 |
| BPD** (%) | 33 | 29 | 32 | 0.96 (0.62, 1.48) | 0.82 (0.43, 1.56) | 0.541 |
| BPD or death (%) | 55 | 47 | 42 | 0.58 (0.41, 0.82) | 0.46 (0.26, 0.79) | 0.005 |
| NEC†† (%) | 21 | 21 | 14 | 0.63 (0.38, 1.03) | 0.62 (0.30, 1.28) | 0.200 |
| NEC or death (%) | 43 | 31 | 26 | 0.45 (0.32, 0.65) | 0.34 (0.25, 0.65) | 0.001 |
| ROP‡‡ requiring treatment (%) | 16 | 19 | 12 | 0.76 (0.42, 1.36) | 1.30 (0.51, 3.12) | 0.615 |
Betamethasone ≤6 hours referent. Adjusted for gestational age, small for gestation, gestational diabetes, race, preeclampsia, multiple birth, outborn, chorioamnionitis, delivery mode and birth year epoch.
P value for adjusted odds ratio or coefficient.
Severe IVH, grade 3 or 4 among infants who survived at least 4 days. N= 639 (some infants died prior to the time the morbidity was able to be determined)
Respiratory Severity Score (RSS) = mean airway pressure x fraction of inspired oxygen. By convention, mean airway pressure = liter flow rate when infants received nasal cannula flows of ≤3 liter/min; measurements made at 24 hours after birth. N= 654 (some infants died prior to the 24-hour time point). Linear regression with bootstrapping coefficient and bias corrected confidence interval reported.
Bronchopulmonary Dysplasia (BPD), physiologic definition by room air challenge at 36 weeks post-menstrual age. N= 528 (some infants died prior to 36 weeks post- menstrual age)
Necrotizing enterocolitis (NEC), Bell’s classification ≥II (treated medically or surgically) or “spontaneous perforations”. N= 564 (some infants died prior to the time the morbidity was able to be determined, i.e., prior to 21 days postnatal age or prior to receiving enteral feedings greater than 80 ml/kg/day)
Retinopathy of Prematurity (ROP), requiring treatment. N= 524 (some infants died prior to the time the morbidity was able to be determined at 38 weeks post-menstrual age)