From: Factors associated with duration of breastfeeding in Spain: a cohort study
Factor | Time ratio (95% CI) | p | Adjusted time ratio (95% CI)a | p |
---|---|---|---|---|
Maternal age (per year) | 1.03 (1.01, 1.04) | 0.002 | 1.02 (1.00, 1.04) | 0.03 |
Maternal educational level | ||||
Primary studies (ref.) | 1 | – | 1 | – |
Secondary studies | 1.26 (0.93, 1.70) | 0.14 | 1.28 (0.95, 1.74) | 0.11 |
Foundation degree | 1.05 (0.83, 1.34) | 0.68 | 0.99 (0.77, 1.26) | 0.92 |
University studies | 1.73 (1.37, 2.17) | < 0.001 | 1.53 (1.21, 1.95) | < 0.001 |
Maternal occupation | ||||
Working (ref.) | 1 | – | ||
Unemployed | 0.99 (0.79, 1.24) | 0.93 | ||
Inactive | 0.84 (0.64, 1.09) | 0.19 | ||
Student | 1.20 (0.51, 2.79) | 0.68 | ||
Smoking in pregnancy | ||||
No (ref.) | 1 | – | 1 | – |
Yes | 0.51 (0.40, 0.66) | < 0.001 | 0.59 (0.46, 0.76) | < 0.001 |
Duration of pregnancy | ||||
≥ 37 weeks (ref.) | 1 | – | 1 | – |
34–36 weeks | 0.75 (0.49, 1.13) | 0.17 | 0.97 (0.62, 1.53) | 0.91 |
< 34 weeks | 0.55 (0.30, 0.98) | 0.04 | 0.91 (0.46, 1.79) | 0.78 |
Type of delivery | ||||
Vaginal (non-instrumental)(ref.) | 1 | – | ||
Instrumental | 0.93 (0.68–1.27) | 0.66 | ||
Cesarean rate | 0.93 (0.76–1.13) | 0.46 | ||
Newborn gender | ||||
Male (ref.) | 1 | – | ||
Female | 0.92 (0.78, 1.10) | 0.37 | ||
Twin pregnancy | ||||
No (ref.) | 1 | – | 1 | – |
Yes | 0.56 (0.37, 0.85) | 0.006 | 0.57 (0.37, 0.89) | 0.01 |
Newborn weight | ||||
< 2500 | 0.62 (0.46, 0.83) | 0.001 | 0.77 (0.53, 1.11) | 0.16 |
2500–4000 g | 1 | – | 1 | – |
> 4000 g | 1.11 (0.81, 1.53) | 0.52 | 1.08 (0.79, 1.48) | 0.63 |