Understanding Intrauterine Growth Restriction

Intrauterine growth restriction (IUGR) is defined as a fetus that is smaller in size than would be expected for the conception age. The threshold generally used for classifying a baby as having intrauterine growth restriction is being smaller than the tenth percentile. This means that over ninety percent of fetuses at the same stage of development are larger than babies classified as having IUGR.

The exact cause of intrauterine growth restriction is not known, but there are several factors thought to contribute to growth restriction in the fetus. Some of these factors are related to the baby or the pregnancy and others are maternal factors. Pregnancy related factors include multiple pregnancies, problems with the placenta and birth defects. Maternal factors include health factors such as heart or kidney disease, substance abuse, malnutrition and smoking cigarettes.