Table 2.
Labor and delivery characteristics by parity
| Nulliparous n=18,245 |
Multiparous n=21,625 |
P* | |
|---|---|---|---|
| Artificial rupture of membrane | 10,780 (59.4) | 14,091 (65.7) | <0.001 |
| Type of labor | <0.001 | ||
| Spontaneous | 4,731 (25.9) | 9,388 (43.4) | |
| Spontaneous, augmented | 7,265 (39.8) | 5,257 (24.3) | |
| Induced | 6,249 (34.3) | 6,980 (32.3) | |
| Induction indication† | <0.001 | ||
| Not induced | 11,996 (65.8) | 14,645 (67.7) | |
| Intrauterine growth restriction | 122 (0.7) | 89 (0.4) | |
| Oligohydramnios | 710 (3.9) | 399 (1.9) | |
| Nonreassuring fetal status | 322 (1.8) | 267 (1.2) | |
| Prelabor rupture of membranes | 834 (4.6) | 333 (1.5) | |
| Macrosomia | 76 (0.4) | 137 (0.6) | |
| Post term | 2,907 (15.9) | 1,874 (8.7) | |
| Elective | 1,029 (5.6) | 3,518 (16.3) | |
| Other or missing indication | 249 (1.4) | 363 (1.7) | |
| Gestational age at delivery, wk | <0.001 | ||
| 39.0 to 39.6 wk | 6,882 (37.7) | 11,491 (53.1) | |
| 40.0 to 40.6 wk | 7,620 (41.8) | 7,771 (35.9) | |
| 41.0 to 41.6 wk | 3,743 (20.5) | 2,363 (10.9) | |
| Regional anesthesia (epidural or spinal) | 16,408 (89.9) | 15,788 (73.0) | <0.001 |
| Time from L&D admission to delivery or cesarean decision, hrs | 11.1 (7.3–16.3) | 6.0 (3.2–9.2) | <0.001 |
| Mode of delivery† | <0.001 | ||
| Non-operative vaginal | 12,012 (65.8) | 19,155 (88.6) | |
| Operative vaginal (forceps or vacuum) | 1,916 (10.5) | 815 (3.8) | |
| Cesarean | 4,316 (23.7) | 1,655 (7.7) | |
| Cesarean indication† | <0.001 | ||
| Not delivered by cesarean | 13,928 (76.3) | 19,970 (92.4) | |
| Nonreassuring fetal status | 1,383 (7.6) | 570 (2.6) | |
| Labor dystocia or failed induction | 2,774 (15.2) | 567 (2.6) | |
| Prior cesarean | 0 (0.0) | 412 (1.9) | |
| Other or missing indication | 160 (0.9) | 106 (0.5) | |
| Male fetal sex | 9,102 (49.9) | 10,851 (50.2) | 0.56 |
| Birthweight, g | 3410 (3148–3700) | 3490 (3215–3780) | <0.001 |
| Birthweight ≥ 4,000 g | 1609 (8.8) | 2658 (12.3) | <0.001 |
L&D, labor and delivery
Data are n (%) or median (IQR) unless otherwise specified
*
Based on χ2 or Wilcoxon
†
Missing in 241 (type of membrane rupture); 13 (induction indication); 1 (regional anesthesia and mode of delivery); 14 (cesarean indication)