Table 1b.
Maternal demographic, obstetric, and neonatal characteristics by timing of amniotomy among term, nulliparous labor inductions in the ARRIVE trial (2014-2017)
| 4 to <6 hours | 6 to <8 hours | 8 to <10 hours | ||||
|---|---|---|---|---|---|---|
| AROM n=402 |
No AROM n=1086 |
AROM n=251 |
No AROM n=771 |
AROM n=192 |
No AROM n=527 |
|
| Maternal demographic characteristics | ||||||
| Maternal age (years) | 24.0 ± 5.0 | 24.1 ± 5.0 | 24.0 ± 5.2 | 24.2 ± 5.1 | 24.0 ± 4.9 | 24.3 ± 5.1 |
| BMI (kg/m2) | 27.1 ± 6.8 | 28.1 ± 7.0 | 28.4 ± 7.5 | 28.0 ± 6.9 | 28.1 ± 7.3 | 28.2 ± 6.9 |
| Race/ethnicity | ||||||
| Non-Hispanic Black | 115 (28.6) | 322 (29.7) | 64 (25.5) | 242 (31.4) | 67 (34.9) | 164 (31.1) |
| Non-Hispanic White | 176 (43.8) | 393 (36.2) | 94 (37.5) | 279 (36.2) | 87 (45.3) | 171 (32.4) |
| Other | 19 (4.7) | 42 (3.9) | 11 (4.4) | 26 (3.4) | 6 (3.1) | 19 (3.6) |
| Hispanic | 92 (22.9) | 329 (30.3) | 82 (32.7) | 224 (29.1) | 32 (16.7) | 173 (32.8) |
| Private insurance | 166 (41.4) | 385 (35.5) | 93 (37.1) | 272 (35.3) | 74 (38.5) | 177 (33.6) |
| Married | 239 (59.5) | 558 (51.4) | 133 (53.0) | 391 (50.7) | 96 (50.0) | 266 (50.5) |
| Tobacco use | 41 (10.2) | 106 (9.8) | 25 (10.0) | 76 (9.9) | 23 (12.0) | 51 (9.7) |
| Obstetric characteristics | ||||||
| Gestational hypertension or preeclampsia | 76 (18.9) | 179 (16.5) | 36 (14.3) | 134 (17.4) | 33 (17.2) | 92 (17.5) |
| Gestational age at delivery (weeks) | 39.7 ± 0.7 | 39.7 ± 0.7 | 39.6 ± 0.7 | 39.7 ± 0.7 | 39.7 ± 0.7 | 39.7 ± 0.6 |
| Indication for induction | ||||||
| Elective | 266 (66.2) | 791 (72.8) | 185 (73.7) | 558 (72.4) | 128 (66.7) | 394 (74.8) |
| Postdates | 59 (14.7) | 120 (11.0) | 28 (11.2) | 87 (11.3) | 25 (13.0) | 58 (11.0) |
| Fetal* | 30 (7.5) | 84 (7.7) | 20 (8.0) | 59 (7.7) | 17 (8.9) | 37 (7.0) |
| Maternal† | 47 (11.7) | 91 (8.4) | 18 (7.2) | 67 (8.7) | 22 (11.5) | 38 (7.2) |
| Modified Bishop score on admission | 5 (4 – 6) | 4 (3 – 5) | 5 (4 – 6) | 4 (2 – 5) | 4 (3 – 5) | 4 (2 – 5) |
| Cervical dilation on admission (cm) | 1 (1 – 2) | 1 (0.5 – 2) | 1 (1 – 2) | 1 (0 – 2) | 1 (0.5 – 2) | 1 (0 – 1.5) |
| Foley balloon for cervical ripening | 212 (52.7) | 725 (66.8) | 150 (59.8) | 540 (70.0) | 136 (70.8) | 377 (71.5) |
| Prostaglandins for cervical ripening | 154 (38.3) | 412 (37.9) | 86 (34.3) | 295 (38.3) | 58 (30.2) | 209 (39.7) |
| Hours from start of oxytocin to membrane rupture | 4.9 ± 0.6 | 11.9 ± 6.9 | 7.0 ± 0.5 | 13.9 ± 7.2 | 8.9 ± 0.6 | 16.2 ± 7.7 |
| Epidural anesthesia | 385 (95.8) | 1028 (94.7) | 242 (96.4) | 728 (94.4) | 183 (95.3) | 495 (93.9) |
| Neonatal characteristics | ||||||
| Male neonate | 185 (46.0) | 547 (50.4) | 131 (52.2) | 387 (50.2) | 93 (48.4) | 269 (51.0) |
| Birthweight (grams) | 3362 ± 397 | 3382 ± 399 | 3377 ± 397 | 3388 ± 404 | 3360 ± 391 | 3404 ± 410 |
Data presented as n (%), mean +/− standard deviation, or median (IQR).
Note: Bolded values represent statistical significance defined as p<0.05.
*
Fetal indications include intrauterine growth restriction, oligohydramnios, non-reassuring fetal status, and macrosomia.
†
Maternal indications include abruption, gestational hypertension or preeclampsia, and chorioamnionitis.
Number of missing values: BMI (n=16), insurance (n=1), modified Bishop score (n=211), cervical dilation on admission (n=147).