Intrauterine Growth Restriction
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Introduction
Intrauterine growth restriction (IUGR) describes babies who are small for gestational age. This commonly defined as a weight below the 10th percentile of what is expected for gestational age.
The Case of Baby Arun
Arun is a boy born at 37 weeks gestational age. His birth weight is x, placing him at the 6% percentile. His head appears to be proportional.
- what might be causing his growth restriction?
- how do you proceed with diagnosis?
Causes and Risk Factors
There are many potential causes of IUGR, and an initial approach to diagnosis depends on symmetry. Asymmetric infants have a relatively normal head circumference but small length and weight, while symmetric infants are small in all parameters. Asymmetry points towards maternal or placental issues, whereby insufficent nutrients reach the fetus, and those that do are preferentially used for head development. Symmetry suggests the growth restriction lies within the fetus.
Asymmetrical growth restrictionmaternal
placenta
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Symmetrical growth restrictioncongenital infections (TORCHES)
chromosomal abnormalities constitutional small size |
Pathophysiology
Signs and Symptoms
- history
- physical exam
History
Review the maternal history of health and pregnancy. Specifically inquire into:
- infections, especially during the first trimester
Family history
- chromosomal abnormalities
Social history
- exposure to chemicals
Physical Exam
Track syphysis to fundal height throughout pregnancy.
Examine the placenta at time of delivery.
Carefuuly measure the weight, length, and head circumference.
Perform a physical exam of the infant to identify any abnormalities, paying particular attention to the heart, lungs, skin, and neurological systems.
Eye exam may reveal cataracts.
Dysmorphic features of the face, ears, and limbs may suggest chromosomal issues.
Investigations
- lab investigations
- diagnostic imaging
Lab Investigations
If no clear cause is found, bloodwork may be performed to investigate for infections. This can include:
- CBC
- liver enzymes
- IgM antibodies for specific infectious agents
- blood gases for metabolic acidosis
Diagnostic Imaging
If concern is present, do ultrasound to assess:
- bpd
- abdomen (most important)
- femur length
Treatments
Infants should be monitored and treated for hypoglycemia. Adequate nutrition should be provided.
Symmetrical growth retardation is usaually treated supportively, paying close attention to blood sugars and temperature.
may be treated in some cases. These include:
- toxoplasmosis: pyrimethamine, sulfadiazine, and folinic acid
- metabolic erroes: specific diet
Consequences and Course
Infants who are small due to maternal or placental issues (assymetric growth restriction) in general do very well.
Symmetrically small infants fare less well, given the severity of many of the causes and a lack of effective treatments.
Resources and References
Topic Development
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