3Â week feeding | |||||
Period 1: 3/6–12 weeks | Never breastfed | Breastfed3 |  |  |  |
 | n | Mean ± SD | n | mean ± SD | P-value2 |
WVZP1 (N = 522) | 60 | 1.58 ± 1.72 | 462 | 0.99 ± 1.60 | <0.01 |
LVZP1 (N = 402) | 46 | 1.69 ± 2.62 | 356 | 1.37 ± 2.44 | 0.41 |
12Â week feeding | |||||
Period 2: 12–24 weeks | Never breastfed | Breastfed3 | P-value2 |  |  |
WVZP2 (N = 494) | 98 | 1.07 ± 1.75 | 394 | 0.64 ± 1.57 | 0.02 |
LVZP2 (N = 477) | 93 | 0.82 ± 2.62 | 382 | 0.85 ± 2.52 | 0.93 |