Table 2 Maternal and infant factors associated with discontinuation of exclusive breastfeeding in Japanese women
Predictor (n with data) | Exclusive breastfeeding [n (%) or mean (SD)] | Non-Exclusive Breastfeeding [n (%) or mean (SD)] | P-value |
|---|---|---|---|
Demographics | |||
 Primiparity (n = 734) | 229 (43.6%) | 120 (57.4%) |  < 0.01 |
 Age in years (n = 734) | 30.0 (4.7) | 29.6 (6.0) | 0.31 |
  < 20 | 11(2.1%) | 13 (6.2%) |  |
 20–30 | 219 (41.7%) | 81 (38.8%) |  |
 30–40 | 280 (53.3%) | 111(53.1%) |  |
  ≥ 40 | 15 (2.9%) | 4 (1.9%) |  |
 Unmarried (n = 734) | 15 (2.9%) | 15 (7.2%) | 0.01 |
 Employed (n = 728) | 322 (61.8%) | 145 (70.0%) | 0.04 |
 Period to return to work after delivery (n = 205) |  |  | 0.11 |
  ≤ 2 months | 10 (6.8%) | 4 (6.9%) |  |
 3–6 months | 17 (11.6%) | 10 (17.2%) |  |
 7–12 months | 102 (69.4%) | 43 (74.1%) |  |
  ≥ 13 months | 18 (12.2%) | 1 (1.7%) |  |
Health behavior | |||
 Active smoking before pregnancy (n = 734) | 71 (13.5%) | 56 (26.8%) |  < 0.01 |
 Number of cigarettes smoked (n = 734) |  |  |  < 0.01 |
 < 1 cigarettes/day | 454 (86.5%) | 153(73.2%) |  |
1–20 cigarettes/day | 69 (13.1%) | 56 (26.8%) |  |
 ≥ 21 cigarettes/day | 2 (0.4%) | 0 (0%) |  |
 Passive smoking before pregnancy (n = 654) | 103 (23.1%) | 72 (34.4%) |  < 0.01 |
 Number of cigarettes smoked by household members (n = 611) |  |  |  < 0.01 |
  < 1 cigarettes/day | 342 (82.8%) | 134(69.2%) |  |
 1–20 cigarettes/day | 64 (51.4%) | 60(30.3%) |  |
  ≥ 21 cigarettes/day | 7 (1.7%) | 1 (0.5%) |  |
 Alcohol use before pregnancy (n = 732) | 90 (17.2%) | 45 (21.5%) | 0.17 |
 Dietary supplement use (n = 732) | 142 (27.1%) | 70 (33.5%) | 0.09 |
Medical History | |||
 Pre-pregnancy weight (kg) (n = 734) | 53.8 (9.3) | 53.7 (9.2) | 0.98 |
 Pre-pregnancy BMI (n = 685) | 21.5 (3.5) | 21.7 (3.7) | 0.53 |
 Weight gain during pregnancy (n = 679) | 9.8 (4.3) | 10.2 (4.2) | 0.29 |
 Food allergy (n = 734) | 47 (9.0%) | 22 (10.5%) | 0.49 |
 Drug allergy (n = 734) | 38 (7.2%) | 10 (4.8%) | 0.32 |
 Bronchial asthma (n = 701) | 33 (6.7%) | 27 (13.2%) |  < 0.01 |
 Underlying maternal disease (n = 734) | 32 (6.1%) | 16 (7.7%) | 0.51 |
 Mastitis (n = 734) | 39 (7.5%) | 8 (3.8%) | 0.09 |
 Infertility treatment (n = 734) | 32 (6.1%) | 16 (7.7%) | 0.51 |
Breastfeeding Behaviour | |||
 Preference for EBF if possible (n = 429) | 304 (99.4%) | 121 (98.4%) | 0.33 |
 Number of times of breastfed/day at one month (n = 650) | 11.0 (3.6) | 10.2 (3.0) | 0.01 |
Family and housing | |||
 Returned to parents’ house to give birth (n = 690) | 135 (27.7%) | 48 (23.6%) | 0.27 |
 Post-discharge living environment (n = 167) |  |  | 0.91 |
 Nuclear family | 33 (29.5%) | 19 (34.5%) |  |
 Living with own family | 59 (52.7%) | 29 (52.7%) |  |
 Living with husband/partner’s family | 20 (17.9%) | 7 (12.7%) |  |
 Detached house (n = 158) | 91 (84.3%) | 37 (74.0%) | 0.13 |
Infant factors | |||
 Vaginal delivery (n = 734) | 444 (84.6%) | 170 (81.3%) | 0.29 |
 Birthweight (n = 734) | 3105 (294) | 3017 (285) |  < 0.01 |
 Gestational age (n = 734) | 39w5d (1w0d) | 39w4d (1w0d) |  < 0.01 |
 Male infant (n = 734) | 248 (47.2%) | 115 (55.0%) | 0.06 |
 5-min Apgar score (n = 734) | 8.9 (0.4) | 8.9 (0.3) | 0.81 |
 NICU admission (n = 734) | 40 (7.6%) | 27 (12.9%) | 0.11 |
 Neonatal jaundice treatment (n = 734) | 29 (5.5%) | 25 (12.0%) |  < 0.01 |
 Umbilical pH (n = 734) | 7.32 (0.55) | 7.31 (0.48) | 0.11 |
 Weight gain at 1-month check-up (n = 659) | 45.7 (10.3) | 42.4 (11.5) |  < 0.01 |