TABLE 5

Adjusted Analysis: The Effect of Total Maternity Leave Length, Paid Maternity Leave Length, and Time of Return to Work on Breastfeeding Initiation Among Women Who Worked in the 12 Months Before Delivery (N = 6150)

CharacteristicsModel 1a (n = 6100)Model 2b (n = 6100)Model 3c (n = 5950)
OR (95% CI)RR (95% CI)OR (95% CI)RR (95% CI)OR (95% CI)RR (95% CI)
Total maternity leave in weeks
    1–6 (reference)1.001.001.001.001.001.00
    7–121.50 (1.16–1.94)1.13 (1.05–1.20)1.20 (0.89–1.61)1.06 (0.96–1.15)1.16 (0.85–1.60)1.05 (0.94–1.15)
    ≥131.58 (1.20–2.08)1.15 (1.06–1.22)1.31 (0.99–1.72)1.09 (1.00–1.17)1.28 (0.95–1.73)1.08 (0.98–1.17)
    Did not take maternity leave1.11 (0.88–1.40)1.04 (0.95–1.11)1.39 (1.04–1.86)1.11 (1.01–1.19)1.26 (0.92–1.72)1.08 (0.97–1.17)
Paid maternity leave in weeks
    0 (reference)1.001.001.001.001.001.00
    1–61.18 (0.91–1.55)1.05 (0.97–1.13)0.83 (0.62–1.11)0.94 (0.83–1.03)0.82 (0.61–1.11)0.93 (0.83–1.03)
    ≥71.47 (1.11–1.94)1.12 (1.03–1.19)0.89 (0.65–1.21)0.96 (0.85–1.06)0.88 (0.64–1.21)0.96 (0.84–1.06)
    Did not take maternity leave1.00 (0.80–1.26)1.00 (0.92–1.07)1.12 (0.86–1.47)1.04 (0.95–1.12)1.03 (0.77–1.38)1.01 (0.91–1.10)
Time of return to work in weeks
    1–6 (reference)1.001.001.001.001.001.00
    7–121.38 (1.05–1.82)1.11 (1.02–1.20)1.18 (0.86–1.61)1.05 (0.94–1.16)1.15 (0.83–1.61)1.05 (0.93–1.16)
    ≥131.37 (0.98–1.91)1.11 (0.99–1.21)1.32 (0.93–1.89)1.10 (0.97–1.21)1.33 (0.94–1.88)1.10 (0.98–1.21)
    Not yet returned to workd1.48 (1.12–1.97)1.14 (1.04–1.22)1.67 (1.24–2.24)1.17 (1.08–1.26)1.46 (1.08–1.97)1.13 (1.03–1.22)
  • Weight variable is W1R0. The corrected RR has been obtained using this formula: RR = OR/([1 − P0)]+ [P0 * OR]), where P0 is the incidence of the outcome (breastfeeding initiation) in the nonexposed group (reference group). Each main independent variable was assessed separately in each of the models without the other main independent variables.

  • a Unadjusted model.

  • b Adjusted for maternal characteristics only (race/ethnicity, age, marital status, education, income status, country of birth, and smoking status).

  • c Adjusted for all control variables (race/ethnicity, age, marital status, education, income status, country of birth, smoking status, birth weight, mode of delivery, birth order, health care professional advice about breastfeeding, separation from child for ≥1 week, child care arrangements, WIC participation within the last 12 months, region of residence, and urbanicity).

  • d Not yet returned to work by the 9-month interview.

  • SOURCE: US Department of Education, National Center for Education Statistics, ECLS-B Longitudinal 9 Month-Preschool Restricted Use data file.