Intrauterine growth retardation, commonly known as IUGR, is a slower than average growth of the foetus inside the mother’s womb and may be due to a variety of reasons. Because of this arrest of foetal growth very early in its prenatal life, there is a reduction in the total number of cells which causes slow growth of the child in later life as well.
The infant's weight is generally rated on a percentile scale which compares his weight with the normal average. The 100th percentile is when the child’s weight exactly matches the average. The lesser the percentile ranking of the infant’s weight, the lower the infant’s weight is as compared to the average. IUGR is defined as the condition when the baby’s weight is less than the 10th percentile (for that month of pregnancy), at birth.
How is it caused?
There are many factors that can cause IUGR, most of which are related to the condition of the pregnant mother. The most common causes are:
Maternal undernutrition – mothers with a pregnancy weight of 40kg or less and a height of 150cm or less are at an increased risk of producing small-for-date (SFD) babies. These babies are those that have a lower than average weight at the time of birth. Small-for-date babies are different from premature babies in that, the latter are born before the expected date.
Pregnancy complications – conditions like increased nausea and vomiting (hyperemesis), preeclampsia, high blood pressure and uterine infections during pregnancy contribute to IUGR.
Heavy smoking by the mother, maternal age less than 20 years and illness during pregnancy, like anaemia, heart and kidney disease.
Abnormalities of the placenta
Multiple pregnancy – more than one foetus in the womb may cause all of them to have lower birth weight.
Genetic abnormalities in the foetus
Birth order – firstborn babies are generally smaller.
What are the symptoms?
IUGR may be suspected if the mother’s uterus is small or a small foetus is detected by the ultrasound scan. The mother may herself feel that the baby is not as big as it should be.
How is it diagnosed?
A prenatal clinical examination or ultrasound scan may show the small size of the foetus. Certain tests for prenatal infection may be done if the retardation is detected before birth. A physical examination of the baby immediately after birth may also confirm that the baby is small-for-date.
An APGAR score is routinely done for all infants immediately after birth. This score checks the development of the infant on five basic parameters. The baby’s breathing effort, heart rate per minute, colour of the body, muscle tone and reflexes are scored for abnormalities. A low score is cause for concern and relevant action is taken. A baby with IUGR may score low on any or all of these scales. The ratings range from 0 to 2, 0 being the lowest and 2 being the strongest or nearest to normal score.
What are the problems that these infants may develop?
SFD infants usually develop problems of breathing soon after birth. Since the temperature regulating mechanisms in these babies may not be fully developed, they are more prone to becoming cold and catch infections. These infections may also be caused due to these babies’ low stores of body fat and glucose. Some of the more severe cases of IUGR may have to be kept on life-support systems like ventilators till their body functions return to normal.
How can it be treated?
There is no specific treatment for the condition. After birth, care is taken to provide a conducive atmosphere for the baby’s growth. A pregnant mother should gain adequate weight by consuming a healthy diet and avoiding alcohol and cigarettes.