Table 3.
The contribution of each group of the Ten Group Classification to the overall obstetric population by race
| Robson group | White (n = 2,874,450) | Black (n = 614,305) | AIAN (n = 37,358) | Asian (n = 272,990) | NHOPI (n = 11,263) | More than one (n = 95,722) |
|---|---|---|---|---|---|---|
| 1 | 16.0% (460331) | 13.6% (83803) | 13.2% (4921) | 21.0% (57324) | 14.3% (1613) | 17.9% (17146) |
| 2a | 8.3% (237497) | 6.6% (40330) | 6.7% (2508) | 7.3% (19965) | 4.9% (549) | 8.4% (8025) |
| 2b | 2.5% (72310) | 2.7% (16558) | 1.2% (445) | 4.0% (10939) | 2.0% (220) | 2.5% (2354) |
| 3 | 28.8% (828874) | 28.2% (173022) | 32.0% (11936) | 29.0% (79058) | 33.4% (3758) | 28.9% (27696) |
| 4a | 13.6% (391576) | 11.6% (71433) | 14.2% (5297) | 8.4% (22944) | 9.6% (1078) | 12.2% (11725) |
| 4b | 3.1% (88888) | 3.8% (23179) | 2.4% (886) | 2.9% (7907) | 2.5% (281) | 2.7% (2624) |
| 5 | 12.3% (352499) | 13.0% (80138) | 11.8% (4426) | 12.8% (34996) | 13.2% (1492) | 11.3% (10810) |
| 6 | 1.2% (34902) | 0.7% (4196) | 0.8% (282) | 1.4% (3918) | 0.8% (86) | 1.0% (951) |
| 7 | 1.9% (53796) | 1.7% (10585) | 2.2% (812) | 1.7% (4731) | 2.6% (293) | 1.7% (1585) |
| 8 | 3.4% (97993) | 4.0% (24824) | 2.8% (1034) | 3.2% (8668) | 2.6% (296) | 3.4% (3261) |
| 9 | 1.2% (34470) | 1.3% (7852) | 1.5% (575) | 1.0% (2805) | 1.8% (200) | 1.2% (1109) |
| 10 | 7.7% (221314) | 12.8% (78385) | 11.3% (4236) | 7.2% (19735) | 12.4% (1397) | 8.8% (8436) |
AIAN American Indian or Alaskan Native, NHOPI Native Hawaiian or Other Pacific Islander