In the first few days after that baby is born it is perfectly normal for their weight to drop. The dropped weight is usually regained by the end of the first week to 10 days, after which they are expected to follow their growth chart on the centile they are born on.
Most new mums are tempted to take their baby for weighing every week. This can be a mistake, especially in breast fed babies it is normal to have peaks in weight gain- meaning they will put on weight over a couple of days and then this will plateau, making it usual for a baby to put on weight one week and then not the next. This can cause concern for even the most confident of mums.
I would recommend that after the first 14 days when your health visitor and midwife will want to keep a close eye on you and your baby that you go to the baby clinic every 2 weeks and not every week for a weigh in, unless of course you are worried. Once your baby is 3 months, and gaining weight well then every 3-4 weeks is usually fine.
A couple of warnings about centile charts (which I personally have a dislike of!) many are based on bottle fed babies- who put on weight at a faster pace than breast fed babies. If your baby is exclusively breast fed it is very normal for them to drop centiles in the first 6 months.
Another important point is that it is very rare for your baby to follow the centile that they are born on. The first 8-10 weeks is them finding their curve, unless you are worried that your baby is dropping weight, is very sleepy or lethargic please don’t worry if they don’t follow their birth curve for those first few weeks.
Please don’t get sucked into the ‘higher your baby is the better you are doing’ that is as ridiculous as thinking that a bigger adult is better than a smaller one! Your babies weight is determined mainly by their genes, if you and your husband are both small/petite or on the shorter side, even if your baby was born on the 91st percentile there is NO way they will follow it and become in that top 9% of the population!
These are natural developments in your babies growth, in a bottle fed baby you will notice by the baby finishing more of their milk- at this point you will naturally increase the amount of feed offered at each feed slightly- there should always be around an ounce of milk left in a babies bottle at the end of each feed.
However in a breast fed baby the ‘dreaded growth spurts’ are seen as a time when your baby will be literally attached to the breast day and night!
There is a reason why your baby needs to feed more during a growth spurt- this is necessary for them to stimulate your body into producing more milk. Without this increased demand their increased milk requirements will not be met.
For this reason it is important to not supplement the feeding in any way with either formula or EBM (expressed Breast Milk). If you do then this can stretch the time that your baby needs to feed more often for. If you persevere then this ‘increased’ feeding should pass in 12-48 hours. At which point your baby should settle back into their previous routine.
The growth spurts typically happen at around the second week, fourth and sixth months.