Growth retardation occurs when your fetus doesn’t develop at a normal rate. It’s widely referred to as intrauterine growth restriction (IUGR). The term intrauterine growth retardation is also used.
Fetuses with IUGR are much smaller than other fetuses of the same gestational age. The term is also used for full-term babies who weigh less than 5 pounds, 8 ounces at birth.
There are two forms of growth retardation: symmetrical and asymmetrical. Children with symmetrical IUGR have a normally proportioned body, they are just smaller than most children of their gestational age. Children with asymmetrical IUGR have a normal sized head. However, their body is much smaller than it should be. On an ultrasound, their head appears to be much larger than their body.
You may not notice any signs that your fetus has growth retardation. Most women are unaware of the condition until they’re told about it during an ultrasound. Some don’t find out until after giving birth.
Children born with IUGR are at higher risk of several complications, including:
- low oxygen level
- low blood sugar
- too many red blood cells
- failure to maintain a normal body temperature
- low Apgar score, which is a measure of their health at birth
- problems feeding
- neurological problems
IUGR occurs for a number of reasons. Your child may have an inherited abnormality in their cells or tissues. They could be suffering from malnutrition or low oxygen intake. You, or your child’s birthmother, may have health problems that lead to IUGR.
IUGR can start at any stage of pregnancy. A number of factors increase your child’s IUGR risk. These factors are divided into three categories: maternal factors, fetal factors, and uterine/placental factors. Uterine/placental factors are also referred to as intrauterine factors.
Maternal factors are health conditions that you, or your child’s birthmother, can have that increase the risk of IUGR. They include:
- chronic diseases, such as chronic kidney disease, diabetes, heart disease, and respiratory disease
- high blood pressure
- certain infections
- substance abuse
Fetal factors are health conditions that your fetus can have that raise the risk of IUGR. They include:
- birth defects
- chromosome abnormalities
- multiple gestation pregnancy
Intrauterine factors are conditions that can develop in your uterus that raise the risk of IUGR, including:
- decreased uterine blood flow
- decreased blood flow in your placenta
- infections in the tissues around your fetus
A condition known as placenta previa can also cause IUGR. Placenta previa occurs when your placenta attaches too low in your uterus.
IUGR is usually diagnosed during a standard screening ultrasound. Ultrasounds use sound waves to check the development of your fetus and your uterus. If your fetus is smaller than usual, your doctor may suspect IUGR.
A smaller than normal fetus may be no cause for concern in early pregnancy. Many women are unsure of their last menstrual period. Therefore, your fetus’s gestational age may not be accurate. The fetus may appear to be small when it’s actually the correct size.
When IUGR is suspected in early pregnancy, your doctor will monitor your fetus’s growth through regular ultrasounds. If your baby fails to grow properly, your doctor may diagnose IUGR.
An amniocentesis test may be suggested if your doctor suspects IUGR. For this test, your doctor will insert a long, hollow needle through your abdomen into your amniotic sac. Then your doctor will take a sample of the fluid. This sample is tested for signs of abnormalities.
Depending on the cause, IUGR may be reversible.
Before offering treatment, your doctor may monitor your fetus using:
- ultrasound, to see how their organs are developing and to check for normal movements
- heart-rate monitoring, to be certain their heart rate increases as it moves
- Doppler flow studies, to make certain that their blood is flowing properly
Treatment will focus on addressing the underlying cause of IUGR. Depending on the cause, one of the following treatment options may be useful:
Increasing Your Nutrient Intake
This ensures that your fetus is getting adequate food. If you haven’t been eating enough, your baby may not have enough nutrients to grow.
You may be put on bed rest to help improve your fetus’s circulation.
In severe cases, an early delivery may be necessary. This allows your doctor to intervene before damage caused by IUGR gets worse. Induced delivery is usually only necessary if your fetus has stopped growing entirely or has serious medical problems. In general, your doctor will probably prefer to allow it to grow for as long as possible before delivery.
Children who have a severe form of IUGR may die in the womb or during birth. Children with a less severe form of IUGR may also have complications.
Children with low birth weight have an increased risk of:
- learning disabilities
- delayed motor and social development
There are no known ways to prevent IUGR. However, there are ways to reduce your baby’s risk.
- eating healthy foods
- taking your prenatal vitamins, with folic acid
- avoiding unhealthy lifestyles, such as drug use, alcohol use, and cigarette smoking