Most babies drop weight in the first few days of life, as their body loses fluids (breastfed babies tend to lose even more as breast milk doesn’t come in properly for a couple of days). This is completely normal, but your health visitor will still want to monitor your baby to make sure he hasn’t lost more than 10 per cent of his body weight, which is a sign of dehydration.
Thankfully, most babies quickly make up for the loss and by around two weeks are back at birth weight. Once a newborn hits the one-month mark, he’ll begin to gain about 700-900g (1.5-2lb) each month. By four months, many babies have doubled their birth weight, and by a year, they’ve often tripled it.
Proportionally speaking, babies gain more weight in their first year than at any other time. This is a good sign as weight gain is one of the best indicators of physical growth there is. That’s why it’s best to get your baby weighed regularly by a health visitor in the first few months. She’ll note where he falls on the growth chart in your red book in terms of weight and percentile (which is based on the percentage of babies his age who weigh this amount). Then, at each subsequent visit, she’ll compare the percentiles to make sure your little one is growing at a normal rate within this range. For instance, if your six-month-old weighs 8.2kg (18lb), according to the growth charts he falls into the 95 percentile, meaning he’s bigger than 95 percent of boys his age, but still within the range of normal. If he were to drop down to the 75 percentile at next month’s visit, your health visitor would try to work out why.
You’ll be able to tell your baby’s gaining weight even without the scales. He’ll grow out of clothes at lightning speed not to mention feel heavier as you carry him around. If you have any concerns, however, speak to your health visitor or GP.