TABLE 4.
Adjusteda associations (95% confidence intervals) of outcomes by distribution point of latent phase of labor duration among nulliparous women
| Outcome | Measure of association | Point of distribution | |||||||
|---|---|---|---|---|---|---|---|---|---|
| <Mean (referent) | Mean | <80th (referent) | 80th | <90th (referent) | 90th | <95th (referent) | 95th | ||
| Amniotomy | aOR | ref | 4.45 (2.62, 7.57) | ref | 3.22 (1.88, 5.51) | ref | 3.18 (1.68, 6) | ref | 2.77 (1.18, 6.49) |
| Oxytocin augmentation | aOR | ref | 4.46 (2.92, 6.82) | ref | 6.39 (4.04, 10.12) | ref | 8.21 (4.57, 14.74) | ref | 11.28 (4.83, 26.36) |
| Labor dystocia diagnosis | aOR | ref | 3.95 (2.7, 5.79) | ref | 5.38 (3.44, 8.4) | ref | 7.51 (4.04, 13.97) | ref | 7.50 (3.13, 17.97) |
| Epidural | aOR | ref | 3.05 (2.12, 4.4) | ref | 3.51 (2.27, 5.44) | ref | 7.07 (3.63, 13.77) | ref | 8.89 (3.33, 23.72) |
| Cesarean delivery | aOR | ref | 1.6 (0.78, 3.29) | ref | 2.12 (0.98, 4.56) | ref | 2.22 (0.90, 5.48) | ref | 2.39 (0.75, 7.61) |
| Postpartum hemorrhage | aOR | ref | 1.21 (0.75, 1.96) | ref | 1.47 (0.85, 2.53) | ref | 1.24 (0.61, 2.52) | ref | 1.12 (0.41, 3.08) |
| NICU admission | aOR | ref | 0.56 (0.27, 1.2) | ref | 0.83 (0.35, 1.98) | ref | 1.18 (0.44, 3.19) | ref | 0.37 (0.05, 2.85) |
| Sensitivity analysis NICUa | aOR | ref | 1.19 (0.41, 3.46) | ref | 2.08 (0.67, 6.48) | ref | 2.03 (0.54, 7.59) | ref | 1.05 (0.13, 8.64) |
| Apgar < 7 at 5 min | aOR | ref | 0.16 (0.02, 1.57) | ref | 0.38 (0.04, 4.07) | ref | 0.75 (0.07, 8.49) | ref | 1.17 (0.08, 16.01) |
| Active phase of labor | aHR | ref | 0.66 (0.55, 0.79) | ref | 0.67 (0.54, 0.82) | ref | 0.58 (0.44, 0.77) | ref | 0.68 (0.47, 0.99) |
| Second-stage labor | aHR | ref | 0.77 (0.65, 0.93) | ref | 0.71 (0.58, 0.88) | ref | 0.77 (0.58, 1.01) | ref | 0.66 (0.45, 0.97) |
Abbreviations: aHR, adjusted hazard ratio; aOR, adjusted odds ratio; NICU, neonatal intensive care unit.
Adjusted for maternal age, maternal height, BMI category, pregnancy weight gain, partner status, gestational diabetes, spontaneous rupture of membranes, group beta streptococcus colonization status, neonatal birthweight, and gestational age.
Neonatal morbidity composite includes these diagnoses before hospital discharge postbirth or as reported by mother at 6 wk postpartum: meconium aspiration, infection, bronchopulmonary dysplasia, cardiac failure, hypovolemic shock, intraventricular hemorrhage, birth trauma, necrotizing enterocolitis, pneumonia, persistent pulmonary hypertension, renal failure, respiratory distress syndrome, Rh disease, seizures, sepsis, hyperbilirubinemia, hospital readmission, other neonatal complications.