Table 2.
Type of labor by completed week of gestation
| Reason for delivery | 39 0/7 to 39 6/7 | 40 0/7 to 40 6/7 | 41 0/7 to 42 2/7 | P for trend* |
|---|---|---|---|---|
| weeks | weeks | weeks | ||
| N=964 | N=1111 | N=427 | ||
|
| ||||
| Spontaneous labor | 735 (76.2) | 733 (66.0)** | 84 (19.7)** | <0.001 |
|
| ||||
| Cesarean delivery | 89 (12.1) | 123 (16.8) | 25 (29.8) | <0.001 |
|
| ||||
| Medically indicated delivery | 229 (23.8) | 378 (34.0) | 343 (80.3) | |
|
| ||||
| Induction | 214 (93.4) | 366 (96.8) | 338 (98.5)** | 0.001 |
|
| ||||
| Cesarean without labor | 15 (6.6) | 12 (3.2) | 5 (1.5) | |
|
| ||||
| Reasons for medically indicated delivery | ||||
|
| ||||
| Postdates | 0 (0.0) | 137 (36.2) | 303 (88.3) | |
|
| ||||
| Hypertension/preeclampsia | 80 (34.9) | 63 (16.7) | 6 (1.7) | |
|
| ||||
| Premature membrane rupture | 58 (25.3) | 51 (13.5) | 8 (2.3) | |
|
| ||||
| Oligohydramnios | 21 (9.2) | 40 (10.6) | 14 (4.1) | |
|
| ||||
| Non-reassuring fetal status | 34 (14.8) | 47 (12.4) | 7 (2.0) | |
|
| ||||
| Other medical reason | 36 (15.7) | 40 (10.6) | 5 (1.5) | |
Data are N (%) unless otherwise specified.
*
Based on Cochran-Armitage trend test.
**
P-value for pairwise comparisons 40 vs. 39 weeks and 41 vs. 39 weeks are <0.05