How Much Weight Should a Newborn Gain in a Month?

Watching your baby's weight during the first few weeks can bring both excitement and worry. You may wonder whether your baby is gaining enough weight, especially after the normal weight loss that occurs soon after birth.

This guide explains what to expect from newborn weight gain in the first month, why babies lose weight after birth, and which signs may show your baby needs extra feeding or medical support.

Once a newborn has regained the weight lost after birth, many healthy term babies gain about 20 to 30 grams a day, or around 150 to 200 grams a week, during the early months. These figures are approximate, and individual growth can vary.

The important thing is to follow your baby's growth over time. Your paediatrician will plot your baby's weight on an appropriate growth chart and look at the overall pattern rather than expecting a specific monthly increase. WHO growth standards include weight-for-age and weight-velocity charts for this purpose.

The first month usually follows this pattern:

• First few days: Your baby loses some weight after birth.
• Around day 5 onwards: Weight loss usually stops and weight begins to increase.
• Around 1 to 2 weeks: Many babies regain their birth weight.
• By 3 weeks: Most babies have regained their birth weight.
• After birth weight is regained: Your baby continues to gain weight as feeding becomes established.

It is normal for newborns to lose some weight during the first few days. Much of this early loss is related to the normal loss of excess fluid after birth.

Your baby may also take small amounts of colostrum during the first few days while breastfeeding establishes. Weight loss usually stops after the first few days, followed by steady weight gain.

Some weight loss is expected, but losing more than 10% of birth weight needs medical assessment. Your healthcare professional may assess feeding, hydration and your baby's overall health to understand why the weight loss has occurred.

For example, if your baby weighs 3 kg at birth, a 10% loss would bring the weight down to about 2.7 kg.

If your baby has not regained birth weight within the expected period, your paediatrician can assess feeding and decide whether your baby needs closer weight monitoring or additional support.

Your baby's growth can vary because of several factors. Your paediatrician considers these factors when assessing weight gain.

Feeding

How well your baby feeds and takes in milk has an important role in early growth. Breastfed newborns commonly feed frequently, often around 8 to 12 times in 24 hours. Your baby's feeding pattern can vary, so look at feeding alongside weight, wet diapers and your baby's behaviour.

If breastfeeding is painful, your baby struggles to latch, feeds poorly or seems unusually sleepy during feeds, seek help from your paediatrician, midwife or lactation professional.

If you use infant formula, prepare it exactly according to the manufacturer's instructions. Do not add extra powder or dilute the formula to change your baby's weight gain.

Birth weight

Your baby's birth weight provides a starting point for monitoring growth. However, you do not need to compare your baby's weekly weight gain with another baby's.

Your paediatrician will plot your baby's measurements on a growth chart and assess how the weight changes over time. WHO growth standards include weight-for-age and weight-velocity standards for monitoring growth.

Prematurity

Babies born prematurely may follow a different growth pattern from babies born at term. Your paediatrician may use corrected age and a growth chart designed for premature babies when assessing growth.

If your baby was born prematurely or had a low birth weight, follow the growth-monitoring plan recommended by your healthcare team rather than comparing your baby's weight with term newborns.

Other factors

Feeding difficulties, poor latch, jaundice, tongue-tie, illness and other medical conditions can affect weight gain.

If your baby is not feeding well or is not gaining weight as expected, your paediatrician can assess the possible cause and recommend appropriate support.

Your baby's weight will be checked during routine newborn and infant health visits. Your healthcare professional will plot the measurements on a growth chart and look at the pattern over time.

You usually don't need to weigh a healthy newborn every day at home. Frequent weighing can make normal short-term changes seem more significant than they are. If your baby has a feeding or growth concern, your healthcare professional may recommend weighing more often.

Along with weight, pay attention to how your baby feeds and behaves.

Signs that your baby may be getting enough milk include:

• Your baby wakes for feeds and feeds actively.
• The number of wet diapers increases during the first few days.
• By around day 5, your baby usually has at least 6 wet diapers in 24 hours.
• Your baby has periods of alertness between feeds.
• Your baby's weight increases over time.

Good newborn care also supports your baby's overall health. This includes caring for your baby's belly button while the umbilical cord stump heals.

Consult your paediatrician if you are concerned about your baby's feeding or weight gain.

Seek medical advice promptly if:

• Your baby continues to lose weight after the first few days.
• Your baby has lost more than 10% of birth weight.
• Your baby has not regained birth weight within the expected period.
• Your baby has fewer wet diapers than expected for their age.
• Your baby is difficult to wake for feeds or has a weak suck.
• Your baby is feeding poorly or has become less interested in feeds.
• Your baby has jaundice along with poor feeding or unusual sleepiness.
• Your baby seems unwell, or you are concerned about their feeding or behaviour.

Your doctor may assess feeding, hydration, weight changes and other signs of illness to understand why your baby is not gaining weight as expected.

Do not give your newborn a weight-gain supplement, herbal product, formula additive or feeding fortifier unless your paediatrician has recommended it.

Some babies may need additional milk, fortified feeds or a different feeding plan because of prematurity, poor weight gain or another medical condition. Your paediatrician will decide what your baby needs based on their health, weight, gestational age and feeding pattern.

If your doctor recommends a supplement or fortifier, follow the instructions carefully. Do not add extra powder or increase the amount to make your baby gain weight faster.

If your baby develops vomiting, diarrhoea, a rash, unusual sleepiness, feeding difficulties or another concerning reaction after starting a recommended product, contact your healthcare professional.

Newborns usually lose some weight during the first few days after birth before starting to gain steadily. Many healthy term babies gain around 20 to 30 grams a day once they have regained their birth weight, but your baby's individual growth pattern matters more than reaching an exact weekly or monthly figure.

Track your baby's feeding, wet diapers, behaviour, and weight measurements during routine health visits. If your baby is feeding poorly, losing too much weight, or not gaining weight as expected, consult your paediatrician.