Table I.
Characteristics of the study participants
| Antibiotic use during pregnancy |
No |
Yes |
||
|---|---|---|---|---|
| Variables | Missing data (%) | Values | Missing data (%) | Values |
| Subjects, no. (%) | 56,245 (71.5) | 22,433 (28.5) | ||
| Maternal demographics | ||||
| Maternal age (y), mean (SD) | 5 (0) | 30.91 (4.94) | 1 (0) | 30.65 (5.11) |
| Parity≧1, no. (%) | 1,452 (2.6) | 32,710 (59.7) | 446 (2) | 13,073 (59.5) |
| Unmarried/divorced/bereaved no. (%) | 1,012 (1.8) | 2,353 (4.3) | 298 (1.3) | 1,075 (4.9) |
| Prepregnancy BMI (kg/m2), mean (SD) | 39 (0.1) | 20.99 (3.11) | 8 (0) | 21.08 (3.19) |
| Preexisting hypertension, no. (%) | 766 (1.4) | 190 (0.3) | 197 (0.9) | 69 (0.3) |
| Preexisting type 1 diabetes, no. (%) | 766 (1.4) | 26 (0.0) | 197(0.9) | 19 (0.1) |
| Preexisting type 2 diabetes, no. (%) | 766 (1.4) | 54 (0.1) | 197 (0.9) | 17 (0.1) |
| Maternal history of allergies, no. (%) | 766 (1.4) | 31,670 (57.1) | 197 (0.9) | 13,292 (59.8) |
| Antipyretic/analgesic use during pregnancy, no. (%) | 6398 (11.4) | 8,854 (17.8) | 1,257(5.6) | 6,560 (31.0) |
| Maternal education, no. (%) | 1240 (2.2) | 382 (1.7) | ||
| Junior high school/high school | 19,622 (35.7) | 8,306 (37.7) | ||
| Technical junior college/technical or vocational college/associate degree | 23,020 (41.8) | 9,195 (41.7) | ||
| Bachelor’s degree/graduate degree | 12,363 (22.5) | 4,550 (20.6) | ||
| Household income, no. (%) | 4844 (8.6) | 1914 (8.5) | ||
| <4 million yen | 20,484 (39.9) | 8,547 (41.7) | ||
| ≥4 but <6 million yen | 17,176 (33.4) | 6,665 (32.5) | ||
| ≥6 million yen | 13,741 (26.7) | 5,307 (25.9) | ||
| Complication of pregnancy or delivery, no. (%) | 1,103 (2) | 21,781 (39.5) | 172 (0.8) | 12,575 (56.5) |
| Morning sickness, no. (%) | 1,217 (2.2) | 365 (1.6) | ||
| Never | 9,560 (17.4) | 3,667 (16.6) | ||
| Having nausea but no vomiting | 23,650 (43.0) | 9,403 (42.6) | ||
| Vomiting but being able to eat | 15,843 (28.8) | 6,466 (29.3) | ||
| Vomiting and being unable to eat | 5,975 (10.9) | 2,532 (11.5) | ||
| Weight gain during pregnancy, mean (SD) | 1,307 (2.3) | 10.39 (5.35) | 238 (1.1) | 10.38 (3.99) |
| Urinary cotinine concentration during pregnancy (T2/T3), no. (%) | 2,035 (3.6) | 722 (3.2) | ||
| <0.31 μg/g creatinine (nonsmoker) | 30,423 (56.1) | 11,758 (54.2) | ||
| 0.31<36.8 μg/g creatinine (passive smoker) | 19,208 (35.4) | 7,817 (36.0) | ||
| ≥36.8 μg/g creatinine (active smoker) | 4,579 (8.4) | 2,136 (9.8) | ||
| Alcohol consumption during pregnancy (T2/T3), no. (%) | 1,406 (2.5) | 426 (1.9) | ||
| Did not drink/stopped drinking before pregnancy | 27,831 (50.8) | 11,072 (50.3) | ||
| Stopped drinking after pregnancy | 25,452 (46.4) | 10,296 (46.8) | ||
| Still drinking, no. (%) | 1,556 (2.8) | 639 (2.9) | ||
| Offspring characteristics | ||||
| Male sex/female sex, no. | 3 (0) | 28,662/27,580 (51.0/49.0) | 0 (0) | 11,546/10,887 (51.5/48.5) |
| Premature birth, no. (%) | 0 (0) | 1,511 (2.7) | 0 (0) | 991 (4.4) |
| Birth weight (g), mean (SD) | 0 (0) | 3,058 (3.60) | 0 (0) | 3,041 (3.77) |
| Breast-feeding to age ≤6 mo, no. (%) | 5,117 (9.1) | 49,842 (97.5) | 2,255 (10.1) | 19,644 (97.4) |
| Pet ownership to age ≤3 y, no. (%) | 9,703 (17.3) | 15,308 (32.9) | 4,107 (18.3) | 6,218 (33.9) |
| Allergic disease to age ≤3 y, no. (%) | ||||
| Preschool asthma | 11,957 (21.3) | 4,789 (10.8) | 5,015 (22.4) | 2,183 (12.5) |
| Wheezing | 13,116 (23.3) | 16,454 (38.2) | 5,518 (24.6) | 7,036 (41.6) |
| FA | 11,957 (21.3) | 5,685 (12.8) | 5,015 (22.4) | 2,291 (13.2) |
| AD | 11,957 (21.3) | 5,021 (11.3) | 5,015 (22.4) | 2,046 (11.7) |
| Eczema | 14151 (25.2) | 12,047 (28.6) | 5,902 (26.3) | 4,777 (28.9) |
| Allergic rhinoconjunctivitis | 11957 (21.3) | 3,565 (8.0) | 5015 (22.4) | 1,589 (9.1) |
| Any allergy disease | 15169 (27) | 24,498 (59.6) | 6,331 (28.2) | 10,059 (62.5) |
BMI, Body mass index.