At 12 weeks of infant age , the intervention was effective in almost doubling the rate of exclusive breastfeeding ( risk ratio 1.92 ; 95 % CI : 1.59-2 .33 ) and increasing infant weight and length-for-age z-scores ( weight difference 0.09 ; 95 % CI : 0.00-0 .18 , length difference 0.11 ; 95 % CI : 0.03-0 .19 ) .