It is perfectly normal for a baby to lose weight during the first few days, but after the third or fourth day they are expected to gain weight, with a minimum of 10g per day. Nathan has been doing just that, going from 3.820kg, 3.580kg, 3.520kg, 3.560kg, 3.570kg. So for now, we're fine. However, he needs to pick up pace soon, and drink more during each feeding session. Still, his bowels and kidneys are doing a good job, proof for that are the loads of diapers we're changing.