Table 2:
Proportion of unplanned cesareans by provider type and unadjusted odds ratios for unplanned cesarean delivery by maternal and pregnancy characteristics, intrapartum interventions, and labor complications, Denver, Colorado, United States, 2005–2012.
| Characteristic | Unplanned Cesarean1 N=58,No.(%) | Successful VBAC N=444, No. (%) | Unadjusted Odds Ratio (95% CI) | P value |
|---|---|---|---|---|
| Delivery mode outcome2 | ||||
| Overall (N=502) | 58 (11.6) | 0.404 | ||
| Midwife (N=286) | 36 (12.6) | |||
| Obstetrician (N=216) | 22 (10.2) | |||
| Maternal characteristics | ||||
| Maternal age (years) | ||||
| 18–24 | 16 (27.6) | 100 (22.5) | 0.93 (0.40–2.18) | 0.38 |
| 25–34 | 32 (55.2) | 286 (64.4) | 0.65 (0.30–1.39) | |
| 35–40 | 10 (17.2) | 58 (13.1) | Reference | |
| Pre-pregnancy BMI3,4 | ||||
| <18.5 | 1 (1.8) | 9 (2.1) | 0.95 (0.12–7.67) | 0.225 |
| 18.5–29.9 | 39 (68.4) | 332 (78.3) | Reference | |
| ≥30 | 17 (29.8) | 83 (19.6) | 1.74 (0.94–3.24) | |
| BMI at delivery3,4 | ||||
| 18.5–29.9 | 25 (43.1) | 215 (48.4) | Reference | 0.486 |
| ≥30 | 33 (56.9) | 229 (51.6) | 1.24 (0.71–2.15) | |
| Gestational weight gain4 | ||||
| Appropriate/Below | 29 (50.9) | 245 (57.8) | Reference | 0.393 |
| Excessive | 28 (49.1) | 179 (42.2) | 1.32 (0.76–2.30) | |
| Race/Ethnicity | ||||
| Hispanic | 26 (44.8) | 225 (50.7) | Reference | <0.05 |
| Black | 13 (22.4) | 46 (10.4) | 2.45 (1.17–5.11) | |
| Non-Hispanic white | 13 (22.4) | 133 (30.0) | 0.85 (0.42–1.70) | |
| Other | 6 (10.3) | 40 (9.0) | 1.30 (0.50–3.35) | |
| Marital status (married or partnered) | 37 (63.8) | 334 (75.2) | 0.58 (0.33–1.03) | 0.079 |
| Maternal height (<60 inches) | 5 (8.6) | 26 (5.9) | 1.52 (0.56–4.12) | 0.561 |
| Smoked during pregnancy | 7 (12.1) | 28 (6.3) | 2.04 (0.85–4.91) | 0.163 |
| Gestational diabetes | 4 (6.9) | 24 (5.4) | 1.30 (0.43–3.88) | 0.759 |
| Obstetrical Characteristics | ||||
| Gravidity | ||||
| 2 | 30 (51.7) | 147 (33.1) | Reference | 0.006 |
| >2 | 28 (48.3) | 297 (66.9) | 0.46 (0.27–0.80) | |
| Parity | ||||
| 1 | 43 (74.1) | 217 (48.9) | Reference | <.001 |
| ≥2 | 15 (25.9) | 227 (51.1) | 0.33 (0.18–0.62) | |
| Successful previousVBAC | ||||
| Yes | 4 (6.9) | 131 (29.6) | Reference | <.001 |
| No | 54 (93.1) | 312 (70.4) | 5.67 (2.01–15.97) | |
| Failed a previous TOLAC | 1 (1.7) | 2 (0.5) | 3.88 (0.35–43.44) | 0.309 |
| Recurring indicationfor cesarean | 33 (56.9) | 162 (36.5) | 2.30 (1.32–4.00) | 0.004 |
| Grobman score (probability)5 | ||||
| <0.65 (low) | 37 (64.9) | 131 (30.9) | 4.14 (2.31–7.40) | <.001 |
| ≥0.65 (high) | 20 (35.1) | 293 (69.1) | Reference | |
| Fetal characteristics | ||||
| Gestational age at delivery (weeks days) | ||||
| 37 0/7 – 38 6/7 | 7 (12.1) | 123 (27.7) | 0.40 (0.17–0.93) | 0.01 |
| 39 0/7 – 40 6/7 | 37 (63.8) | 262 (59.0) | Reference | |
| 41 0/7 – 41 6/7 | 14 (24.1) | 59 (13.3) | 1.68 (0.85–3.31) | |
| Clinical suspicion of macrosomia present6 | 2 (3.5) | 10 (2.3) | 1.55 (0.33–7.26) | 0.638 |
| Intrapartum interventions | ||||
| Status of onset of labor | ||||
| Spontaneous | 14 (24.1) | 289 (65.1) | Reference | <.001 |
| Augmentation | 31 (53.5) | 124 (27.9) | 5.16 (2.65–10.04) | |
| Induction | 13 (22.4) | 31 (7.0) | 8.66 (3.73–20.07) | |
| Artificial rupture of embranes | 30 (51.7) | 233 (52.5) | 0.97 (0.56–1.68) | >.99 |
| Episiotomy performed | NA | 10 (2.3) | NA | 0.387 |
| Received epidural | 34 (58.6) | 210 (47.3) | 1.58 (0.91–2.75) | 0.124 |
| Prostaglandin use | 2 (3.5) | 7 (1.6) | 2.23 (0.45–11.00) | 0.607 |
| Pitocin | 42 (72.4) | 147 (33.1) | 5.30 (2.89–9.75) | <.001 |
NA = not applicable
, N for each column may vary due to missing variables for each factor.
, Control (reference) group was care with CNM. Delivery mode for our model outcome was unplanned cesarean. P value for only this characteristic applies to comparison of successful VBAC vs unplanned cesarean by provider type.
, Mean BMI (kg/m2)(24)
, Pre-pregnancy weight, height, or weight at delivery was incomplete for twenty-one patients based on chart review.
, Unable to calculate the Grobman probability score if components were missing. Optimal 0.65 cutoff was determined by receiver operator characteristics analysis.
, Based on documented clinical assessment not uniform estimated fetal weight definition.