Table 4. Adjusted odds ratios of and differences in adverse perinatal outcomes by starting dose of oxytocin augmentation in nulliparas.
| Starting dose | |||
|---|---|---|---|
| 1 mU/min. N=1319 | 2 mU/min. N=2383 | 4 mU/min N=4073 | |
| OR | aOR* (95% CI) | aOR* (95% CI) | |
| Cesarean delivery | 1.0 | 1.0 (0.8 – 1.3) | 0.9 (0.7 – 1.1) |
| Meconium stain | 1.0 | 1.1 (0.9 – 1.4) | 0.9 (0.7 – 1.1) |
| Chorioamnionitits | 1.0 | 1.2 (0.9 – 1.6) | 1.0 (0.8 – 1.2) |
| Intrapartum fetal distress | 1.0 | 1.1 (0.8 – 1.5) | 0.8 (0.6 – 1.2) |
| Shoulder dystocia | 1.0 | 0.7 (0.3 – 1.6) | 1.0 (0.5 – 2.0) |
| 3rd/4th degree perineal laceration | 1.0 | 1.0 (0.7 – 1.4) | 1.1 (0.8 – 1.5) |
| Maternal complication composite index# | 1.0 | 0.9 (0.7 – 1.2) | 1.1 (0.9 – 1.4) |
| Newborn resuscitation¶ | 1.0 | 1.1 (0.5 – 2.7) | 1.0 (0.5 – 2.3) |
| Newborn fever | 1.0 | 1.1 (0.8 – 1.6) | 1.1 (0.8 – 1.5) |
| NICU admission | 1.0 | 1.1 (0.8 – 1.5) | 1.0 (0.7 – 1.3) |
| Birth injury | 1.0 | 0.8 (0.4 – 1.6) | 1.3 (0.7 – 2.3) |
| 5 min. Apgar score < 7 | 1.0 | 0.4 (0.1 – 0.97) | 0.4 (0.1 – 0.9) |
| Neonatal complication composite index† | 1.0 | 1.0 (0.7 – 1.6) | 0.9 (0.6 – 1.4) |
| Difference | Difference* (95% CI) | Difference* (95% CI) | |
| Estimated blood loss (ml) | Ref. | -2.8 (-28.1, 22.6) | -11.6 (-35.7, 12.5) |
| NICU length of stay (day) | Ref. | 0.35 (-1.31, 2.0) | 1.18 (-0.4, 2.8) |
| 1st stage (admission to full dilation) (h) | Ref. | -0.8 (-1.1, -0.5) | -1.3 (-1.7, -1.0) |
| 2nd stage of labor (min.) | Ref. | 1.2 (-15.6, 18.1) | -8.8 (-24.7, 7.2) |
Maternal complication composite index includes: intrapartum placental abruption, postpartum hemorrhage, intrapartum and postpartum blood transfusion and hysterectomy.
Newborn resuscitation includes: intubation, chest compression, epinephrine or other related medicine and continuous positive airway pressure.
Neonatal complication composite index includes: asphyxia, hypoxia-ischemic encephalopathy, neonatal seizure, neonatal death, respiratory distress syndrome, continuous positive airway pressure, ventilation use and transient tachypnea.
For adjusted odds ratios, a multivariable logistic regression model was used to adjust for maternal age, race/ethnicity, insurance type, use of fetal scalp electrode, epidural analgesia, birthweight, gestational age, body mass index at admission, cervical dilation, effacement, fetal station, frequency of uterine contraction at admission, cervical dilation at oxytocin administration, and hospital site. For adjusted difference, a generalized linear mixed model was used to adjust for the above factors. Hospital was used as a random effects variable.