Definition of Intrauterine growth restriction:

Intrauterine growth restriction (IUGR) refers to the poor growth of a baby while in the mother's womb during pregnancy. Specifically, it means the developing baby weights less than 90% of other babies at the same gestational age.

Causes, incidence, and risk factors:

Many different things can lead to intrauterine growth restriction (IUGR). An unborn baby may not get enough oxygen and nutrition from the placenta during pregnancy because of:

• High altitudes
• Multiple pregnancy (twins, triplets, etc.)
• Placenta problems
• Preeclampsia or eclampsia

Congenital or chromosomal abnormalities are often associated with below-normal weight. Infections during pregnancy that affect the developing baby, such as rubella, cytomegalovirus, toxoplasmosis, and syphilis may also affect the weight of the developing baby.

Risk factors in the mother that may contribute to IUGR include:

• Alcohol abuse
• Clotting disorders
• Drug addiction
• High blood pressure or heart disease
• Kidney disease
• Poor nutrition
• Smoking

If the mother is small, it may be normal for her the baby to be small, but this is not due to IUGR.

Depending on the cause of IUGR, the developing baby may be symmetrically small, or have a head that is normal size for gestational age, while the remainder of it's body is small.