TABLE 3

Odds of Becoming Overweight at the Age of 24 Months According to Age at First Exposure to Antibiotics and Number of Exposures <24 Months

Antibiotic Exposure	Boys		Girls
Antibiotic Exposure	aOR	95% CI	aOR	95% CI
Unexposed	1.00	Reference	1.00	Reference
Age at first exposure, mo
Any antibiotics
<6	1.34^a	1.06 to 1.66	1.16	0.87 to 1.56
6–11	1.26^a	1.02 to 1.45	1.14	0.92 to 1.42
12–17	1.18	0.88 to 1.32	1.08	0.85 to 1.38
18–23	1.25	0.99 to 1.61	1.15	0.87 to 1.52
Penicillins
<6	1.28	0.99 to 1.62	1.20	0.87 to 1.66
6–11	1.29^a	1.04 to 1.49	1.20	0.97 to 1.50
12–17	1.28	0.95 to 1.42	1.04	0.81 to 1.33
18–23	0.95	0.78 to 1.28	1.15	0.87 to 1.52
Cephalosporins
<6	1.44	0.97 to 2.35	1.25	0.67 to 2.35
6–11	1.44^a	1.04 to 1.84	1.18	0.79 to 1.76
12–17	1.46^a	1.06 to 1.82	1.27	0.88 to 1.82
18–23	1.10	0.78 to 1.43	1.11	0.75 to 1.64
Macrolides
<6	1.65^a	1.09 to 2.31	1.53	0.90 to 2.60
6–11	1.41^a	1.09 to 1.70	1.11	0.82 to 1.50
12–17	1.10	0.84 to 1.34	1.28	0.95 to 1.71
18–23	1.42^a	1.18 to 1.93	1.21	0.88 to 1.65
No. of exposures <24 mo
Any antibiotics
1	1.16	0.92 to 1.48	1.03	0.81 to 1.32
2–3	1.28^a	1.04 to 1.59	1.14	0.91 to 1.42
≥4	1.27^a	1.04 to 1.55	1.19	0.96 to 1.48
Penicillins
1	1.13	0.90 to 1.41	1.11	0.89 to 1.40
2–3	1.29^a	1.05 to 1.58	1.19	0.96 to 1.48
≥4	1.35^a	1.07 to 1.69	1.11	0.85 to 1.44
Cephalosporins
1	1.39^a	1.10 to 1.76	1.05	0.80 to 1.38
≥2	1.15	0.84 to 1.58	1.46^a	1.03 to 2.05
Macrolides
1	1.20	0.96 to 1.49	0.94	0.94 to 1.50
≥2	1.47^a	1.16 to 1.86	0.88	0.88 to 1.55

Statistical adjustments included maternal smoking after first trimester, parental relationship, mode of delivery, birth weight, and birth length for boys; maternal smoking after first trimester, mode of delivery, and birth weight for girls.
↵^a P value <.05