Table 1 Maternal and girls’ characteristics by breastfeeding duration: KPNC puberty study
Breastfeeding duration | Not breastfed | < 6 months | ≥6 months | P- value |
|---|---|---|---|---|
N = 3331 (mother-daughter pairs) | 511 | 1123 | 1697 | |
Maternal characteristics | N (%) or Mean (SD) | Â | ||
 Age at delivery (years) | 29.3 (5.7) | 30.3 (5.4) | 31.3 (5.1) | < 0.001 |
 Maternal BMI (kg/mm2) | ||||
  < 25 | 179 (37.0) | 474 (43.7) | 736 (46.6) | < 0.001 |
  25- < 30 | 137 (28.3) | 355 (32.7) | 486 (30.8) |  |
  ≥ 30 | 168 (34.7) | 256 (23.6) | 356 (22.6) |  |
 Race/Ethnicity | ||||
  Non-Hispanic White | 171 (33.5) | 434 (38.7) | 797 (47.0) | < 0.001 |
  Asian/Pacific Islander | 127 (24.9) | 307 (27.3) | 363 (21.4) |  |
  Hispanic | 149 (29.2) | 294 (26.2) | 439 (25.9) |  |
  African American | 64 (12.5) | 88 (7.8) | 98 (5.8) |  |
 Parity | ||||
  0 | 204 (39.9) | 504 (44.9) | 686 (40.4) | 0.02 |
  1 | 179 (35.0) | 405 (36.1) | 654 (38.5) |  |
  2+ | 128 (25.1) | 214 (19.1) | 357 (21.0) |  |
 Education | ||||
  High school or less | 190 (37.2) | 342 (30.5) | 400 (23.6) | < 0.001 |
  Some college | 187 (36.6) | 375 (33.4) | 478 (28.2) |  |
  College/university | 93 (18.2) | 281 (25.0) | 513 (30.2) |  |
  Postgraduate | 41 (8.0) | 125 (11.1) | 306 (18.0) |  |
Girls’ characteristics | N (%) or Mean (SD) |  | ||
 Prepubertal BMI | ||||
  ≥ 85th percentile | 180 (35.2) | 355 (31.6) | 469 (27.6) | < 0.01 |