Actually I mmother of preterm twin boys(29 weeks 2days) now they are 6 months + (DOB: 5 june 2021) and their weights are 7.3 kg and 7kg. My babies used to take good feedings almost 6 ounces per feedings and 6-7 feeding a day. No mother's milk only formula.Now all of sudden their feeding decreases so doctor said change the milk powder change they suggest me similac now I m confused between similac and similac advance I used to take nan pro previously. please suggest. #asktheexperts