Dr Sarah Brewer

Sarah Brewer advises on how your baby grows

Measuring your baby's rate of growth is an important way of assessing his general health and nutrition. In some cases, poor growth - or failure to thrive - may be the first sign that something is wrong. It is therefore important to see your health visitor regularly so she can record your baby's changing height and weight.

A newborn baby boy normally weighs between 2.7kg (5lb 13oz) and 4.3kg (9lb 6oz) at full term. Girls tend to be slightly lighter at 2.6kg (5lb 10oz) to 4.1kg (9lb) although a proportion of healthy babies naturally fall outside this range. During the first week of life, it is normal for a newborn baby to lose a little weight, but try not to worry about this as they usually regain their birth weight by the age of 10 days.

Your baby will put on weight at around 28g (1oz) per day until the age of 3 months. The average baby has doubled his or her birth weight by the age of four to five months and trebled it by 12 to 14 months. After this time, weight increases by around 3kg (6.5lbs) per year, although some children grow faster and some more slowly than others.

The average newborn baby is 50cm (19.5 - 20.5 inches) long. During their first year they gain another 25 - 30 cm (10 - 12 inches) in length, and during their second year they gain another 12 - 15cms (5 - 6 inches). By his or her second birthday, your baby will be around half his or her adult height. You can estimate your baby's potential height from the height of both parents, assuming they are of normal stature:

Start by adding together the father's height (cm) plus the mother's height (cm), divide by two to obtain the mid parent height.

If your baby is a boy, add 7cm to the mid parental height. His final height is likely to fall within 10cm of this final figure.

For girls, take away 7cm from the mid parental height. Her final height is likely to fall within minus 8.5cm of this final figure.