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. Author manuscript; available in PMC: 2022 Dec 1.
Published in final edited form as: Birth. 2021 May 28;48(4):501–513. doi: 10.1111/birt.12560

TABLE 4.

Frequency of obstetric/neonatal events for nulliparous individuals who experienced IOL versus EM (inclusive) in two academic midwifery settings

39 weeks
40 weeks
41 weeks
IOL
EM 39
IOL
EM 40
IOL
EM 41
n = 186 n = 3266 n = 214 n = 2250 n = 452 n = 709
Rationale for labor induction (may have more than one rationale)
 Prelabor rupture of membranes 63 (33.8) 119 (3.6) 63 (29.4) 56 (2.5) 50 (11.1) 6 (0.8)
 Elective postdates 0 (0.0) 208 (6.3) 8 (3.7) 200 (8.9) 153 (33.8) 47 (6.6)
 Medical or obstetric risks/conditions 88 (47.3) 356 (10.9) 90 (42.1) 266 (11.8) 189 (41.8) 77 (10.9)
 Advanced maternal age 3 (1.6) 28 (0.9) 10 (4.7) 18 (0.8) 12 (0.4) 6 (0.8)
 Social/other 12 (6.4) 24 (0.7) 15 (7.0) 9 (0.4) 9 (1.9) 0 (0.0)
 None of the above/missing rationale 34 (18.2) 2772 (84.8) 55 (25.7) 1915 (85.1) 55 (12.2) 49 (6.9)
Neuraxial analgesia 120 (71.9) 1710 (60.4)* 135 (75.8) 1226 (62.0)* 291 (75.7) 397
(62.2)*
HTN disorders 63 (34.4) 209 (6.4)* 47 (23.2) 123 (5.5)* 51 (11.3) 35 (4.9)*
Suspected IAI 11 (8.5) 169 (6.7) 13 (8.3) 132 (7.5) 33 (9.8) 53 (9.2)
Augmentation of spontaneous labor n/a 956 (39.1) n/a 689 (41.8) n/a 268
(47.4)
Instrument-assisted vaginal birtha 5 (3.5) 115 (4.4) 8 (4.8) 80 (4.6) 14 (4.7) 26 (5.0)
Episiotomya 6 (4.2) 123 (4.7) 5 (3.0) 93 (5.4) 17 (5.7) 32 (6.2)
3rd/4th-degree lacerationa 3 (2.1) 182 (7.0)* 11 (6.3) 129 (7.5) 21 (7.1) 37 (7.2)
Postpartum hemorrhageb 16 (9.5) 267 (8.9) 14 (7.1) 211 (10.3) 51 (13.0) 90 (14.1)
Blood transfusion 4 (2.6) 35 (1.2) 4 (2.3) 27 (1.3) 4 (1.0) 11 (1.7)
Macrosomiac 13 (6.9) 479 (14.7)* 29 (13.6) 402 (17.8) 97 (21.5) 161 (22.7)
Shoulder dystociaa 3 (2.1) 65 (2.5) 6 (3.9) 46 (2.7) 13 (4.4) 15 (2.9)
NICU admission 8 (4.4) 151 (4.7) 10 (4.8) 114 (5.1) 24 (5.4) 40 (5.7)
Composite neonatal outcome 8 (4.3) 157 (4.8) 14 (5.1) 119 (5.3) 25 (5.5) 43 (6.1)

Note: Composite outcome =any of the following NICU admission, meconium aspiration, stillbirth, perinatal death.

Suspected IAI =diagnosis of maternal fever during or after labor or intra-amniotic infection during labor.

Abbreviations: HTN, hypertensive; IAI, intra-amniotic infection; NICU, neonatal intensive care unit.

Missing data: 535 on epidural variable.

a

Limited to vaginal birth.

b

Defined as 1000 mL or higher blood loss. Data for exclusive EM rates versus IOL were significant in the 40th and the 41st weeks (13.7% and 20.7%, respectively, P = 0.01).

c

Data for macrosomia with exclusive EM were significant at 39th week = 17.4%, P < 0.001; at 40th week = 22.2%, P < 0.004; and at 41st week = 32.7%, P = 0.002.

*

sig < 0.05.