Maternal characteristics
| Characteristic | Pre-intervention | Post-intervention | P value |
| (n=4912) | (n=8747) | ||
| Race and ethnicity | 0.024 | ||
| Non-Hispanic white | 1773 (36) | 2931 (34) | |
| Non-Hispanic black | 940 (19) | 1789 (20) | |
| Hispanic | 1804 (37) | 3332 (38) | |
| Non-Hispanic Asian | 365 (7) | 648 (7) | |
| Other | 30 (1) | 47 (1) | |
| Age at delivery (years) | 0.867 | ||
| <18 | 56 (1) | 97 (1) | |
| 18–25 | 1129 (23) | 2032 (23) | |
| 26–35 | 2915 (59) | 5219 (60) | |
| >35 | 812 (17) | 1399 (16) | |
| Insurance | 0.013 | ||
| Medicaid | 1872 (38) | 3559 (41) | |
| Commercial | 2906 (59) | 4992 (57) | |
| International or other | 84 (2) | 126 (1) | |
| Self-pay | 50 (1) | 70 (1) | |
| BMI at delivery (kg/m2 ) | 0.122 | ||
| <18.5 | 1 (0) | 4 (0) | |
| 18.5–25 | 425 (9) | 673 (8) | |
| 25–30 | 1417 (29) | 2378 (27) | |
| 30–35 | 1256 (26) | 2065 (24) | |
| 35–40 | 717 (15) | 1246 (14) | |
| >40 | 496 (10) | 898 (10) | |
| Missing | 600 (12) | 1483 (17) | |
| Nulliparous on admission | 2048 (42) | 3592 (41) | 0.472 |
| Gestational age at delivery (median (IQR)) | 39 (37.7, 39.9) | 39 (37.6, 39.7) | 0.585 |
| Prior caesarean birth | 1071 (22) | 1918 (22) | 0.867 |
| Multiple gestation | 153 (3) | 210 (2) | 0.013 |
BMI, body mass index.