An intrauterine growth restriction occurs when the fetus does not grow as it should during pregnancy. In this case, the fetal weight is below the 10th percentile for its gestational age, or the number of weeks since the last menstrual period. A fetus with IUGR may develop and be healthy, but complications during delivery and pregnancy may occur.
The exact cause of IUGR is unknown, but it may involve a combination of factors that affect the blood supply, oxygen, and nutrients to the fetus. These factors may include:
Placental problems, such as placenta previa, placental abruption, or placental insufficiency, that interfere with the function or attachment of the placenta, the organ that connects the fetus to the uterus and provides nourishment and waste removal
Umbilical cord problems, such as umbilical cord compression, knotting, or twisting, that reduce the blood flow or oxygen delivery to the fetus
Maternal problems, such as high blood pressure, diabetes, kidney disease, heart disease, anemia, malnutrition, smoking, alcohol use, or drug abuse, that affect the health or blood circulation of the mother
Fetal problems, such as chromosomal abnormalities, genetic disorders, infections, or multiple gestations, that affect the growth or development of the fetus
Environmental factors, such as exposure to toxins, pollutants, or radiation, that harm the fetus or the placenta
This is indicated by the fetal size that is smaller than expected for the gestational age, which can be detected during prenatal visits by measuring the fundal height, which is the distance between the pubic bone and the top of the uterus. IUGR may be detected if the fundal height is lower than expected. However, fundal height measurements are not very accurate and vary according to the position of the fetus, the amount of amniotic fluid, or the mother's body type.
Other symptoms of IUGR may include:
Decreased fetal movement or activity
Abnormal fetal heart rate or rhythm
Low amniotic fluid level or oligohydramnios
Premature rupture of membranes or water breaking
Preterm labor or contractions
To confirm the diagnosis of IUGR, the doctor may order some tests to assess the fetal growth, well-being, and possible causes of the condition. These tests may include:
Ultrasound, which uses sound waves to create images of the fetus and the placenta, and measure the fetal weight, length, head circumference, and abdominal circumference
Doppler ultrasound, which uses sound waves to measure the blood flow and pressure in the umbilical cord and the fetal blood vessels
Biophysical profile, which combines an ultrasound and a nonstress test to evaluate the fetal movement, breathing, muscle tone, heart rate, and amniotic fluid level
Amniocentesis, which involves taking a sample of the amniotic fluid that surrounds the fetus and testing it for infections, genetic disorders, or fetal lung maturity
Blood tests, which involve taking a sample of the mother’s blood and testing it for infections, antibodies, or other conditions that may affect the fetus
It depends on the severity of the condition, the gestational age of the fetus, and the underlying cause of IUGR as to how it should be treated. Some possible treatments include improving fetal growth, preventing or treating complications, and ensuring a safe delivery.
Monitoring, which involves regular ultrasounds, tests, and prenatal visits to check the fetal growth, well-being, and possible complications
Medications, which may include blood pressure medications, blood thinners, steroids, or antibiotics, to treat the maternal or fetal conditions that may cause or worsen IUGR
Nutrition, which may include dietary supplements, intravenous fluids, or tube feeding, to provide adequate calories, protein, and fluids to the mother and the fetus
Bed rest, which may involve lying on the left side, elevating the legs, or avoiding strenuous activities, to improve the blood circulation and oxygen delivery to the fetus
Delivery, which may involve inducing labor or performing a cesarean section, to deliver the baby when the risks of staying in the womb outweigh the benefits, usually after 34 weeks of gestation or earlier if there are signs of fetal distress or severe complications
There is no sure way to prevent IUGR, but some measures may help reduce the risk or severity of the condition. These include:
Having regular prenatal care and screenings to monitor the fetal growth and detect any problems early
Taking prenatal vitamins and folic acid supplements to prevent neural tube defects and other birth defects
Eating a balanced and nutritious diet and drinking plenty of water to provide enough nutrients and hydration to the fetus
Quitting smoking, avoiding alcohol and drugs, and limiting caffeine intake to prevent harmful effects on the fetus and the placenta
Managing chronic conditions and infections and taking medications as prescribed by the doctor to control the blood pressure, blood sugar, or other factors that may affect the fetal growth
Avoiding exposure to toxins, pollutants, or radiation that may harm the fetus or the placenta
During pregnancy, intrauterine growth restriction occurs when a fetus does not grow as expected. With proper diagnosis, treatment, and care, most cases of IUGR can be managed and result in a healthy baby. IUGR can affect the development and health of the fetus and increase the risk of complications during pregnancy and delivery.
