Table 3. Duration of second stage of labor and rates, and risks of umbilical artery acidosis, birth asphyxia-related complications and admission to NICU.
|
Acidosisa (N=360) |
Birth asphyxia-related complicationsb (N=269) |
Admission to NICU (N=2733) |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| N totalc | % | aRRd | (95% CI) | N total | % | aRRd | (95% CI) | % | aRRd | (95% CI) | |
| 33 429 | 1.08 | 42 539 | 0.63 | 6.42 | |||||||
| Second stage (h) | |||||||||||
| <1 | 10 518 | 0.99 | 1.00 | Reference | 13 558 | 0.42 | 1.00 | Reference | 4.97 | 1.00 | Reference |
| 1 to <2 | 9690 | 1.12 | 1.10 | (0.84–1.45) | 12 225 | 0.53 | 1.19 | (0.83–1.70) | 6.02 | 1.22 | (1.10–1.35) |
| 2 to <3 | 6130 | 1.27 | 1.19 | (0.88–1.60) | 7710 | 0.77 | 1.59 | (1.10–2.31) | 7.11 | 1.41 | (1.26–1.57) |
| 3 to <4 | 4115 | 0.92 | 0.77 | (0.52–1.14) | 5238 | 0.74 | 1.56 | (1.04–2.35) | 7.92 | 1.57 | (1.39–1.77) |
| ⩾4 | 2976 | 1.04 | 0.84 | (0.55–1.28) | 3808 | 1.29 | 2.46 | (1.66–3.66) | 9.45 | 1.80 | (1.58–2.04) |
Abbreviations: aRR, adjusted relative risk; CI, confidence interval; HIE, hypoxic ischemic encephalopathy; MAS, meconium aspiration syndrome; NICU, neonatal intensive care unit.
a
Acidosis: umbilical artery acidosis, pH <7.05 and BE <−12.
b
Birth asphyxia-related complications include any of the following conditions: HIE, hypothermia treatment, neonatal seizures, MAS or advanced resuscitation after birth (heart compressions or intubation).
c
Missing data on pH and/or BE: N=9110.
d
Adjusted for: maternal characteristics: maternal age, height, BMI, smoking, hypertensive disease and diabetes. Delivery and fetal characteristics: onset of delivery (spontaneous or induction), oxytocin before retracted cervix and gestational length at birth.