In this lecture, we will discuss
failure to thrive in the infant.
Failure to thrive is sub-optimal weight
gain and growth in infants and toddlers
when compared to peers on
standardized growth charts.
There are many causes to failure to thrive,
and there may be multiple factors that are
affecting a child’s inability to grow.
This can be medical or
they can be psychosocial.
When we suspect
failure to thrive,
we will typically plot children on a
growth curve, as you can see here.
And we’ll have another lecture on growth
curves and how we watch these children.
But typically, failure
to thrive is when we see
weight below the second
percentile for age
and gender on more
than one occasion.
Typically, we will expect to
see a weight of less than 80%
than what is ideal for that age.
And we also call failure to thrive when
children are dropping off their growth curve,
for example, more than two major
percentage lines in a six-month period.
When you look at these two charts here,
you can see two children who are growing.
On the middle of this slide, we
can see a child who started off
at a reasonable
weight after birth,
and then has been tracking
appropriately below the line.
This child may not
have failure to thrive
even though we’re seeing multiple
points below the second percentile
because this child is continuing
to track at that percentile.
Chances are this child may
have a genetic syndrome
or something else that’s
causing to not grow well.
This is a patient we would be concerned about
and will work up for a failure to thrive,
but we may eventually just accept this
is where this child is going to be.
On the flipside, on the
far end of this slide,
we can see a child who was born in a particular
weight which is a little bit higher,
and then it’s tracking along a percentile
that is reasonably appropriate.
That child likely does not
have failure to thrive.
So what are the causes of failure to thrive?
There are many, and let’s break
them down to large groups.
So in the first group, we have inadequate
intake or absorption of calories.
So if a child is not absorbing or
is not taking enough calories,
they’re not going to grow,
or it’s possible a child might have inefficient
or defective ability to use those calories,
or a child may have excessive
Let’s look at all these three
So for inadequate
intake or absorption,
there are many potential
causes of failure to thrive.
There can be non-organic or environmental
causes and there can be organic causes.
First, let’s look at
Certainly, a lack of available food or child
abuse or neglect are high in the list.
In fact, child neglect is by far
and away the number one cause of
infants who have
failure to thrive.
Psychosocial deprivation or not
paying attention to a child
may cause a child
to not want to eat,
and that may in turn reduce the
amount of available calories.
In the organic list, some children may have
an impaired ability to suck or swallow,
which is hampering their
ability to absorb calories.
They may have a chronic illness,
which is making them not have
much hunger or drive to eat.
In the inadequate
we think of children who
have excessive vomiting
or children with very severe
Keep in mind especially with
that these are the children we’re
going to treat for reflux.
We don’t treat children
for reflux typically,
unless they’re having
problems with weight gain.
Children may have malabsorption.
In other words, they can’t
absorb the calories that
they're otherwise eating adequately.
There are few diseases that can cause this.
One might be celiac disease.
Celiac disease is an autoimmune
response to gluten in the diet,
which blunts the ability of that
intestine to absorb calories.
Cystic fibrosis patients
frequently have malabsorption
as a result of pancreatic insufficiency.
Patients with milk protein
intolerance when still unrecognized
may have an allergic reaction
in their intestinal wall,
which is preventing them from
adequately gaining calories.
Children with necrotizing
enterocolitis in the newborn period,
especially premature children,
may have sections of intestine
removed as a surgical option
to prevent them from dying of NEC.
Those children then have a short
gut for the rest of their lives
and may have problems
So children with short gut syndrome
may present with failure to thrive.
There are other categories where children
are adequately getting the nutrients but
they just can’t utilize them correctly.
There are some syndromes such
as chromosomal abnormalities
where children can’t
utilize their nutrition.
Children with severe prematurity or
IUGR, intrauterine growth restriction,
may have a problem utilizing
Certainly, children with
will have a problem utilizing nutrients.
If I have a problem breaking down
proteins and digesting them,
I might not be able to
get those calories.
Another example in the metabolic contingency
would be congenital hypothyroidism.
These children have a
hard time growing.
Children with congenital infections may
have a harder time utilizing nutrients
maybe through hepatic failure
or other reasons like that.
And certainly, children with storage
disorders will have problems.
Lastly, children with metabolic diseases
like amino acid or organic acid disorders
may have problems utilizing
Some patients may be able to eat
and use nutrients appropriately,
but simply have such
high metabolic demands
that they aren’t able to keep
up with their body’s own needs.
These children will have
a hard time growing.
Examples would be a patient
where the revved-up
body’s metabolic demands
are too high for what a
child can catch up with.
This is all so true of
patients with cystic fibrosis
or respiratory effort might require
more metabolic requirements.
Malignancies are classic.
So, weight loss in
malignancy is not uncommon.
Patients with chronic infections
may have a problem keeping up
with their body’s
An example would be HIV.
Children with immunodeficiency are especially
prone to getting chronic infections,
and these children sometimes have
problems gaining weight as well.
Congenital heart disease commonly
presents with failure to thrive.
In fact, that may be the
And likewise, again, children with
amino acid and organic acid disorders
also have increased metabolic requirements,
which drive some of their
failure to thrive.