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Pediatrics / Children's Health

Baby Weight: How Much Weight Should A Baby Gain?

By Dayyal Dg.Twitter Profile | Updated: Friday, 05 April 2024 14:11 UTC
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High angle baby on weighing machine.
High angle baby on weighing machine. Freepik / @freepik

Following the arrival of your newborn, it's only natural to be captivated by their weight. Indeed, it's one of the initial inquiries people make once they learn of your baby's gender. Just like adults, babies exhibit a wide array of shapes and sizes. However, as your infant progresses, their weight serves as a crucial indicator of healthy feeding habits and overall well-being. While it's essential to monitor your baby's weight gain or loss, it's common for parents to feel anxious about their little one's size.

This apprehension is understandable, yet it's vital to recognize that your midwife conducts regular checkups to track your baby's weight, while a health visitor also assesses length and head size. These professionals are there to offer support in the event of significant weight loss or if your baby fails to regain birth weight within two weeks. Consequently, they will inquire about your feeding routine and may even request to observe breastfeeding to ensure optimal growth and nourishment for your baby.

Determining Your Baby's Weight

The weight of your newborn is influenced by both genetics and your health and nutrition during pregnancy. While it's natural to focus on your baby's weight at birth, it's crucial to recognize that various factors can affect their weight and growth during pregnancy.

Throughout your pregnancy, the midwife will conduct fundal height measurements, assessing the distance from the pubic bone to the top of the uterus in centimeters. These measurements are recorded in your notes to monitor consistency and ensure proper development. If any concerns arise, you may undergo a growth scan. It's important to understand that monitoring isn't solely about the baby's weight but also involves tracking consistency throughout pregnancy. Typically, baby boys tend to weigh slightly more than baby girls, with distinct growth patterns reflected in different centile charts available through resources like the Royal College of Paediatrics and Child Health website.

Newborn Weight Fluctuations

Every infant experiences a growth pattern from birth, often beginning with weight loss. This phenomenon is particularly common in breastfed babies, who may lose up to 10% of their birth weight in the initial days. However, they usually regain this weight by around day 10. The initial weight loss is attributed partly to the expulsion of excess fluid present at birth and partly to the adjustment period for both the baby in nursing and the mother's milk production, especially if breastfeeding.

Frequency of Weighing Your Baby

While it's understandable to feel concerned about your baby's weight, frequent weighing isn't necessary after the first two weeks following birth. As a general guideline:

  • Monthly weigh-ins are recommended up to six months of age.
  • From 6 to 12 months, weighing every two months is sufficient.
  • Beyond the age of one, weighing every three months is adequate.

Tracking Your Baby's Weight

You have the freedom to weigh your baby as frequently as you wish, and you need not wait for scheduled appointments. Local baby clinics or consultations with your health visitor are accessible avenues for weight checks. However, your midwife may opt for more frequent weigh-ins if developmental concerns arise.

Recording Your Baby's Weight

Following the later stages of pregnancy or postpartum, you will receive a "little red book" from your doctor or midwife. This booklet serves as your baby's personal child health record (PCHR). Despite its daunting title, it's a valuable tool for documenting your baby's weight and height. Some parents also use it to track vaccinations and illnesses. Ensuring the book stays updated with your baby's growth facilitates effective monitoring and serves as a nostalgic keepsake for the future.

Understanding Baby Weight Percentile

Within the little red book, you'll utilize a centile chart to record your baby's weight and growth. These charts delineate the growth patterns of healthy boys and girls. While babies are expected to gain weight steadily within a particular centile range, being at the extreme ends of the chart doesn't imply being under or overweight. Though initially daunting, your health visitor will guide you through interpreting and tracking your baby's development, emphasizing the uniqueness of each child's growth trajectory.

Recommended Weight Gain

During the initial weeks, your baby typically gains between 175g to 225g (6oz to 8oz) per week. By six months, they often double their birth weight, with subsequent weight gain gradually decelerating. While centile charts offer guidelines, occasional deviations may occur due to growth spurts, illness, adaptation to solid foods, or increased activity levels. If concerns arise regarding your baby's growth, consulting your health visitor is advisable.

Baby Weight Reference Chart

Below is an excerpt of average baby weights in the first year for both boys and girls, sourced from the World Health Organization (WHO). While this serves as a guide, consulting your midwife or doctor is recommended if concerns regarding your baby's weight arise.

Age50th centile weight for baby boys50th centile weight for baby girls
Birth 3.5 kg (7.8lbs) 3.4 kg (7.8lbs)
1 month 4.4 kg (9.7lbs) 4.2 kg (7.8lbs)
2 months 5.2 kg (11.5lbs) 4.8 kg (10.5lbs)
3 months 6 kg (13.2lbs) 5.4 kg (12lbs)
4 months 6.7 kg (14.8lbs) 6.2 kg (13.7lbs)
5 months 7.4 kg (16.3lbs) 6.7 kg (14.7lbs)
6 months 7.9 kg (17.4lbs) 7.2 kg (15.8lbs)
7 months 8.4 kg (18.5lbs) 7.7 kg (17lbs)
8 months 8.9 kg (19.6lbs) 8.1 kg (18lbs)
9 months 9.3 kg (20.5lbs) 8.5 kg (18.7lbs)
10 months 9.7 kg (21.4lbs) 8.8 kg (19.4lbs)
11 months 10 kg (22lbs) 9.2 kg (20.3lbs)
12 months 10.3 kg (22.7lbs) 9.5 kg (21lbs)

Understanding Premature Baby Weight

When a baby is born before completing 37 weeks of gestation, they are classified as premature. Premature infants have distinct nutritional requirements compared to full-term babies, as they undergo accelerated growth to catch up with their peers.

Premature babies also follow a modified weight chart tailored to their specific needs. For comprehensive guidance on monitoring and assessing the weight and overall health of preterm infants, the Royal College of Paediatrics and Child Health offers valuable resources and information.


  • The WHO Child Growth Standards, Accessed 5 April 2024
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