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Pediatrics/is 7.5kg Weight ok for nine month old boy or is he underweight


Hello doctor, my nine month old son weighs 7.5kg and his length is 70cms and his HC is 46cms.  His birth weight was 2.7kgs. He climbed the weight percentile between 4 to 6month of his life. He was on 12percentile. On 4month he was 6.2kg, on 6th month he was 6.9kg (9percentile) and now at 9month he has just gained 600gms and lands himself on 6percentile. He maintains himself good on height and HC percentiles. Should I be worried? I read that below 5percentile is failure to thrive. He is a happy baby, army crawls, rolls, sits, now trying to pull to stand. He drinks formula and gets three meals of purée food consisting of cereal, fruits, veggies, lentils, chicken eggs etc. what is ideal weight for this age group of Indian baby boy (if ethnicity plays a role in growth of babies of different origin).Thank you for any input.  Warm regards, Manisha"

Brief answer: Your son's weight is just fine.

Long answer: Babies gain about three times their birth weight by the age of one year. As your son was born 2.7 kg, he is expected to reach an average weight of 8.1 kg by 12 months of age. As he is 7.5 kg already, I guess he is doing just fine. The rate of growth keeps decreasing throughout infancy. At birth and for the first few months, the weight gain is about 1 kg/month. At 6-9 month, the gain drops to about 0.5 kg/month, and from 9-12 months, and during most of the second year of life, the rate of increase will be just 0.25 kg/month.


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Dr. Taher Kagalwala


I come from India, and have been practising since 29 years. I am specially interested in infections, asthma, newborn care and parenting. I have authored a book on Parenting.It is called "Child Care: From Birth to Eighteen". The e-book is now available on
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Qualified Pediatrician practising since 29 years.
Currently working in the United Kingdom. You may reach me on my cell number +447440622670 or email me on only if I have not responded to your query here in a reasonable time. If you directly call me or email me, I might not be able to respond. Thank you for understanding. Please do not Whatsapp me.

Indian Academy of Pediatrics, life member. Mumbai Branch of the I.A.P., life member. Genetics Chapter of the I.A.P.

Indian Pediatrics, Indian Journal of Pediatrics, Toxicology Abstracts.

M.D., M.R.C.P.C.H. (U.K.), Ph. D. (U.S.A.) D.C.H.

Awards and Honors
Gold Medallist in D.C.H., April, 1985
Highest aggregate marks in University of Mumbai, for M.D. ( Pediatrics ), October 1986.
Passed out with distinction from the Royal College of Paediatrics and Child Health, U.K. in 2015.

Past/Present Clients
1. Municipal Corporation of Greater Mumbai (K.E.M. Hospital) 2. Private consulting practice. Worked as the Asst. Paediatrician and DNB Teacher at Masina Hospital. Also visiting Saifee Hospital, Mumbai. 3. Ministry of Health in Kingdom of Saudi Arabia as a Specialist Paediatrician. 4. Now with the NHS, UK as a Specialist Paediatric Registrar at Blackpool, Lancashire, UK.

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