Hello XXXXXXX ,

Thanks for posting on XXXXXXX

The normal weight of a baby girl at 3.5 months should be around 5-6 kg and so 3.9 kg. The main reason for a low weight-for-age (underweight) is malnutrition and in your daughter's case it might be due to malabsorption at the level of the small intestines. If you say she has been having colics then that might be the reason for that. If you are breast feeding and give normally daily between 8-10 good feeds and your daughter is still not gaining weight properly, then I suggest you see a pediatrician as soon as possible. According to WHO weight-for-age z-scores (SD< -3) you daughter is having severe form of underweight/malnutrition (i.e if my calculations are exact).
I suggest you see a pediatrician as soon as possible.

Hope this helps you and your daughter.

Dr. Bernard

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Hello,

thanks for updating,

Neonates and young infants with malabsorption syndromes are at particularly high risk for chronic diarrhea and malnutrition. Clinical malabsorption could be as a result of a congenital or acquired defect (and given your baby's age and presentation the former is likely) that affect one or more of the different steps in the intestinal hydrolysis and subsequent transport of nutrients. Food (carbohydrate, fat, or protein) malabsorption is caused by a disorder in the intestinal processes of digestion, transport, or both of these nutrients across the intestinal mucosa into the systemic circulation. Either a congenital abnormality in the digestive or absorptive processes or, more commonly, a secondarily acquired disorder of such processes may result in malabsorption. Given that they are several enzymes responsible for digestion of the various food particles, it will not be easy to sort out which particular gut defect is responsible for this. All the 3 major food types are responsible for growth and development in children and any of them could be responsible if few quantities are absorbed by the baby's intestines. They are a wide range of both congenital and/or acquired disorders that could be responsible and that will require that your pediatrician (with sub-specialty in pediatric gastroenterology) looks more closely into it.
We have:
- celiac disease (in its entiretyie, including the forms without overt malabsorption is by far the most common inherited malabsorption syndrome)
- cystic fibrosis ( is the second most common malabsorption syndrome)
- others (rare).
Given that the child's general health is still in tact, there is the possibility of associated vitamin and/or mineral deficiencies.
Also if your baby was born premature or with low birth weight for gestational age, then it will also be possible to relate that to the present low weight-for-age (but being too low is a sign of severe malnutrition and so rule's out possibility of prematurity or low-birth weight to be the cause).
Now lets look at his diet proper. The proper amount of fluid for most young children is around 100 mL/kg/d (so breast milk is exclusive for now and should be the only source of fluid). I suggest you start drawing out milk from breast and measuring exact quantities daily, you can divide that into 8-10 good feeds making about 9ml every 2-3 hours.

You should note that failure to identify the cause of malabsorption can result in the misdiagnosis of a physiologic syndrome as a behavioral disorder.
Laboratory tests that may help orient towards malabsorption are:
- Stool analysis: to determine presence of reducing substances, pH level, no bile acids, daily stool fat and intake quantity monitored, large serum proteins, presence of infections etc
- urine analysis: could also help if large quantities of malabsorbed substances are found
- CBC: rule out megaloblastic anemia
- Total serum proteins and albumin levels may be lower
- Other tests to determine if malabsorption is the cause could also be performed by your doctor (s).

Your daughter's condition need to be investigated thoroughly and the cause will be found subsequently, then appropriate treatment will follow.

Hope this helps and wish you the best.
Dr. Bernard

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Hello XXXXXXX,

Thanks for writing back. I took some more time to write in detail because of the way you presented her situation and the fact that you have seen several pediatrician and since I did some research on child nutrition, I thought it wise to provide you with much information. Try to go through the info I have provided and use what you can get from it.

Wish you and your daughter the best and please if you are satisfied, do accept my answer.
Dr. Bernard

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