Intrauterine growth restriction (IUGR) is a condition where a baby in the womb does not grow at the expected rate during pregnancy. IUGR is defined as weighing less than 9 out of 10 babies (below the 10th percentile) of the same age. There are two types of IUGR: symmetrical IUGR, where all parts of the babys body are similarly small in size, and asymmetrical IUGR, where the babys head and brain are the expected size, but the rest of the babys body is small.

IUGR can happen because the fetus doesnt get enough nutrients and nourishment, which can occur if there is a problem with the placenta, the mother has a medical condition such as lupus, anemia, or clotting problems, has high blood pressure (hypertension), is carrying a baby that has a genetic disorder or birth defect, or is pregnant with multiples (such as twins or triplets) .

Doctors check for IUGR by measuring the mothers belly from the top of the pubic bone to the top of the uterus, which is called the uterine fundal height, and by using ultrasounds to check the babys growth, movements, blood flow, and fluid around the baby. If IUGR is suspected, doctors might also do fetal monitoring to track the babys heart rate and other tests to screen for infection or genetic problems.

IUGR increases the risk that the baby will die inside the womb before birth, so if a healthcare provider thinks a mother might have IUGR, she will be monitored closely, and depending on the results of tests, the baby may need to be delivered early. To prevent IUGR, mothers should not drink alcohol, smoke, or use recreational drugs, eat healthy foods, and get regular prenatal care.