Understanding Weight Gain and Weight Loss in Newborns

Once your baby is born, you’ll soon become familiar with the regular weigh-ins for your pēpi over the coming weeks and months; it’s one of the key indicators of your baby’s health and wellbeing.


In the first six weeks after birth, your LMC or the nurses and midwives providing your postnatal care will make sure your baby is on track and growing appropriately. Following this, your pēpi will be weighed at your appointments with your Well Child Tamariki Ora nurse.

Know that it is common for newborns to lose weight in the first days of life. Medical professionals consider it acceptable for an infant to lose up to 10% of their total body weight in the first week, but most babies should be back at their birth weight by two weeks after birth. As a general guide, it’s expected that a healthy newborn baby will gain around 150-200 grams per week for the first three months.

If you hear terms like ‘failure to thrive’ or ‘poor growth’, this means that your baby’s growth is much lower than expected or that they have dropped centiles in the growth charts. In this instance, the doctor, midwife or nurse will assess the cause/s of the weight loss or low weight gain and make a plan with you to help your baby grow optimally.