TABLE 2.
Maternal and infant characteristics of IFPS II participants by prepregnancy BMI category1
| BMI category |
||||
| Underweight/normal weight (<25.0 kg/m2; n = 1406) | Overweight (25.0–29.9 kg/m2; n = 741) | Obese (≥30.0 kg/m2; n = 677) | 2 | |
| Social knowledge [% (n)] | <0.0001 | |||
| 0 people/do not know | 11.4 (160) | 13.7 (100) | 18.7 (125) | |
| 1–2 people | 20.9 (292) | 21.7 (159) | 23.6 (158) | |
| 3–5 people | 26.3 (368) | 29.7 (218) | 27.6 (185) | |
| >5 people | 41.4 (578) | 34.9 (256) | 30.1 (202) | |
| Social influence [% (n)] | 0.02 | |||
| Low | 26.6 (374) | 27.6 (205) | 31.6 (214) | |
| Medium | 33.6 (473) | 35.0 (259) | 35.9 (243) | |
| High | 39.8 (559) | 37.4 (277) | 32.5 (220) | |
| Attitudes and behavioral beliefs [% (n)] | 0.40 | |||
| Poor | 9.1 (128) | 10.8 (80) | 11.8 (80) | |
| Fair | 20.8 (293) | 20.6 (153) | 20.2 (137) | |
| Good | 70.1 (985) | 68.6 (508) | 68.0 (460) | |
| Maternal confidence [% (n)]3 | <0.0001 | |||
| Not confident | 5.4 (63) | 8.8 (55) | 10.3 (54) | |
| Neutral | 21.0 (244) | 26.4 (166) | 27.2 (142) | |
| Confident | 73.6 (854) | 64.8 (407) | 62.5 (326) | |
| Education [% (n)] | 0.0002 | |||
| High school graduate or less | 19.9 (257) | 18.4 (125) | 24.0 (152) | |
| Some college | 37.3 (480) | 43.9 (299) | 42.7 (270) | |
| College graduate | 42.8 (551) | 37.7 (256) | 33.3 (211) | |
| Income [% (n)] | 0.005 | |||
| <185% of PIR | 38.1 (536) | 41.7 (309) | 45.9 (311) | |
| 185–350% of PIR | 36.8 (51) | 35.9 (266) | 35.0 (237) | |
| >350% of PIR | 25.1 (353) | 22.4 (166) | 19.1 (129) | |
| Race-ethnicity [% (n)] | 0.0002 | |||
| Non-Hispanic white | 82.9 (1135) | 86.5 (622) | 87.0 (576) | |
| Non-Hispanic black | 4.3 (59) | 5.2 (37) | 4.7 (31) | |
| Non-Hispanic other | 6.7 (92) | 2.2 (16) | 3.3 (22) | |
| Hispanic (any race) | 6.1 (83) | 6.1 (44) | 5.0 (33) | |
| Smoking [% (n)] | 0.82 | |||
| Yes | 9.5 (133) | 9.1 (67) | 10.1 (68) | |
| No | 90.5 (1269) | 90.9 (670) | 90.0 (607) | |
| Married [% (n)] | 0.77 | |||
| Yes | 79.6 (1029) | 79.4 (544) | 80.9 (516) | |
| No | 20.4 (263) | 20.6 (141) | 19.1 (122) | |
| Planned return to work postpartum [% (n)] | 0.66 | |||
| Not planning to return to work | 38.4 (536) | 40.4 (298) | 39.2 (263) | |
| ≤6 wk | 19.2 (268) | 19.0 (140) | 20.3 (136) | |
| 7–12 wk | 28.0 (390) | 27.9 (206) | 29.0 (194) | |
| >12 wk | 14.4 (201) | 12.7 (94) | 11.5 (77) | |
| Actual time of return to work [% (n)] | 0.70 | |||
| Did not return to work | 43.3 (524) | 43.9 (285) | 44.6 (261) | |
| ≤6 wk | 11.2 (136) | 13.5 (88) | 10.6 (62) | |
| 7–12 wk | 25.3 (306) | 24.3 (158) | 25.3 (148) | |
| >12 wk | 20.2 (245) | 18.3 (119) | 19.5 (114) | |
| Past breastfeeding experience [% (n)] | 0.23 | |||
| Yes | 53.2 (727) | 55.6 (392) | 51.0 (337) | |
| No | 46.8 (640) | 44.4 (313) | 49.0 (324) | |
| Intended breastfeeding duration [% (n)]3 | 0.61 | |||
| ≤6 mo | 33.2 (389) | 35.3 (224) | 32.1 (169) | |
| 6–12 mo | 52.8 (619) | 49.4 (314) | 52.4 (276) | |
| >12 mo | 14.0 (164) | 15.3 (97) | 15.5 (82) | |
| Mode of delivery [% (n)] | <0.0001 | |||
| Vaginal | 79.5 (1116) | 69.9 (518) | 59.0 (399) | |
| Cesarean | 20.5 (288) | 30.1 (223) | 41.0 (277) | |
| Gestation duration (wk) | 39.3 ± 1.2 (1406)4 | 39.3 ± 1.3 (741) | 39.2 ± 1.2 (677) | 0.17 |
| Infant birth weight (g) | 3398 ± 448 (1445) | 3499 ± 471 (757) | 3532 ± 477 (686) | <0.0001 |
1
IFPS II, Infant Feeding Practices Study II; PIR, poverty income ratio.
2
Significance was determined by using the chi-square test for categorical variables and ANOVA for continuous variables.
3
In women who intended to breastfeed.
4
Mean ± SD; n in parentheses (all such values).