Table 3.
Comparison of women who formula-fed because of concern about radioactive contamination or other reasons and women who breastfed exclusively
| Formula-fed because of concern about radioactive contamination (n = 1154) | Formula-fed for other reasons (n = 4535) | Breastfed exclusively (n = 2575) | Formula-fed because of concern about radioactive contamination versus breastfed exclusively | Formula-fed for other reasons versus breastfed exclusively | |
|---|---|---|---|---|---|
| n (%) | n (%) | n (%) | p valuea | p valuea | |
| Disaster-related factors | |||||
| Residential region | |||||
| Within evacuation area | 163 (14.1) | 580 (12.8) | 281 (10.9) | <0.01 | 0.02 |
| Outside evacuation area | 991 (85.9) | 3955 (87.2) | 2294 (89.1) | ||
| Continuation of scheduled antenatal care | |||||
| Yes | 845 (73.8) | 3709 (82.4) | 2077 (81.2) | <0.001 | 0.23 |
| No | 300 (26.2) | 794 (17.6) | 480 (18.8) | ||
| Switched to different medical institution of own accord | |||||
| Yes | 233 (20.2) | 797 (17.6) | 587 (22.8) | 0.08 | <0.001 |
| No | 921 (79.8) | 3738 (82.4) | 1988 (77.2) | ||
| Maternal factors | |||||
| Age (years) | |||||
| <35 | 939 (81.4) | 3557 (78.4) | 2138 (83.0) | 0.22 | <0.001 |
| ≥35 | 215 (18.6) | 978 (21.6) | 437 (17.0) | ||
| Parity | |||||
| Primipara | 284 (24.6) | 1340 (29.5) | 654 (25.4) | 0.61 | <0.001 |
| Multipara | 870 (75.4) | 3195 (70.5) | 1921 (74.6) | ||
| Depressive symptoms | |||||
| Yes | 462 (40.5) | 1147 (25.6) | 647 (25.4) | <0.001 | 0.90 |
| No | 678 (59.5) | 3336 (74.4) | 1896 (74.6) | ||
| Obstetric factors | |||||
| Duration between disaster and delivery (weeks) | |||||
| <23 | 705 (61.1) | 2110 (46.6) | 1235 (48.0) | <0.001 | 0.26 |
| ≥23 | 449 (38.9) | 2422 (53.4) | 1340 (52.0) | ||
| Type of pregnancy | |||||
| Natural pregnancy | 1110 (96.4) | 4325 (95.5) | 2473 (96.3) | 0.79 | 0.13 |
| Other typesb | 41 (3.6) | 203 (4.5) | 96 (3.7) | ||
| Illness during pregnancy (either before or after the disaster) | |||||
| Yes | 312 (27.0) | 1048 (23.1) | 570 (22.1) | <0.01 | 0.35 |
| No | 842 (73.0) | 3487 (76.9) | 2005 (77.9) | ||
| Delivery method | |||||
| Vaginal delivery | 887 (78.6) | 3506 (78.5) | 2130 (83.8) | <0.001 | <0.001 |
| Cesarean section | 241 (21.4) | 959 (21.5) | 413 (16.2) | ||
| Child-related factors | |||||
| Sex of child | |||||
| Male | 598 (52.1) | 2331 (51.8) | 1310 (51.2) | 0.60 | 0.64 |
| Female | 549 (47.9) | 2171 (48.2) | 1249 (48.8) | ||
| Birth weight (g) | |||||
| <2500 | 81 (7.1) | 376 (8.3) | 154 (6.0) | 0.22 | <0.001 |
| ≥2500 | 1065 (92.9) | 4130 (91.7) | 2407 (94.0) | ||
| Congenital anomaly | |||||
| Yes | 25 (2.3) | 130 (3.0) | 56 (2.3) | 1.00 | 0.08 |
| No | 1085 (97.7) | 4250 (97.0) | 2428 (97.7) | ||
| Neonatal asphyxia | |||||
| Yes | 14 (1.3) | 53 (1.2) | 18 (0.7) | 0.12 | 0.05 |
| No | 1101 (98.7) | 4316 (98.8) | 2472 (99.3) | ||
aChi square test was used
bOther types include ovarian hyperstimulation, artificial insemination, and in vitro fertilization