Fetal growth restriction, also called intrauterine growth restriction, is a condition where the unborn baby is smaller than it has to be in the womb due to its inability to grow at anormal rate. When FGR is mild, it does not cause any long-term problems, and most babies catch up on weight and height by the age of two years. But when this condition is severe, it can seriously harm the baby after birth. The extent of harm depends on the severity of FGR, the cause and when it starts during pregnancy.
There are many possible causes of fetal growth restriction. However, one of the most common causes is placental insufficiency. The placenta is a tissue that connects the fetus and the mother .It carries nutrients and oxygen to the baby and helps release waste from the baby. The other causes for this condition can be due to health issues in the mother, like
● High blood pressure
● Heart disease
● Advanced Diabetes
● Inflexions like syphilis, rubella, toxoplasmosis, and cytomegalovirus
● Lung disease
● Kidney disease
● Anaemia
● Malnutrition
● Sickle cell anemia
● Autoimmune disease
● Smoking, alcohol consumption or using drugs
Other IUGR causes include multiple gestation (twins or triplets)—chromosomal defects in the fetus, or living 5000 feet above the ground level.
Even though twins are smaller than average babies, fetal growth restriction affects up to25% of twin pregnancies.
● There is an uneven share of nutrients and oxygen between the twins. This results in one of the twins being smaller, and it is called selective uterine growth restriction.
● They share the same blood vessels and, due to this, have a severe condition called TTTS or twin-twin transfusion syndrome. In this condition, the twins do not have an equal exchange of blood and put both babies at risk.
● The twins share the same amniotic sac, which can cause the umbilical cords to become entangled. This cuts off the blood supply to both or one of the twins.
FGR may lead to:
● Decrease in oxygen levels
● Hypoglycemia (low blood sugar)
● Trouble with vaginal delivery stress
● Premature birth
● Low birth weight
● Less resistant to infections
● Low Apgar score (a test to check the physical condition of the new born right after birth to determine if special medical care is needed)
● High RBC (red blood cell) count
● Problems controlling the body temperature
● Meconium aspiration (when the baby takes in its stools while in the womb) leads to breathing issues.
In severe cases, fetal growth restriction leads to long-term growth issues and can also lead to stillbirth. There is no way to prevent FGR, but with a healthy lifestyle, you can reduce the chances of it.
One of the main symptoms of this condition is that the baby is small for the gestational age. Specifically, if the baby's projected weight is lower than 90% of babies of the same gestational age or below the 10th percentile, it can indicate FGR. Depending on the FGR, the baby may look malnourished or small. They may look pale and thin and have dry and loose skin. The umbilical cord is often dull and thin instead of shiny and thick. However, a thing to note is that if your baby is born small, that does not mean it is FGR.
There are many ways healthcare providers estimate the baby's size during pregnancy. One of the most common and simplest ways is to measure the distance of the top of the uterus (mother’s fundus) to the baby’s pubic bone. Typically, the measurement is in centimetres and corresponds to the number of weeks you are pregnant. For instance, in the 20 weeks, the measurement will be around 20 cm. If the measurement is lower, the baby will not grow as expected. The healthcare provider may suspect fetal growth restriction if the baby is in the less than 10 percentile range for the gestational age.
The other ways to diagnose this condition and also determine the health of the baby include:
This is one of the main diagnostic tests done to check the growth and development of the baby in the uterus. The ultrasound has sound waves that create images of the baby and is a safe test. This exam allows the doctor to see the baby with an instrument by moving it over the mother’s belly to measure the baby’s abdomen and head. It helps the doctor to evaluate the baby's weight. Ultrasound can also check the quantity of amniotic fluid in the uterus. A low quantity of amniotic fluid may mean FGR. If that happens, you may need several follow-up ultrasounds to check the placental blood flow, the baby’s movement and growth, and, if you have twins, whether they share the placenta.
This is another test that uses sound waves. It measures the speed and amount of blood flow in the blood vessels. Healthcare providers perform this test to determine the blood flow in the baby’s brain vessels to the umbilical cord.
This is a test in which sensitive electrodes are placed over the mother’s belly. The electrodes are held by a stretchable, lightweight band fixed to a monitor. The sensors measure the pattern and rate of the baby’s heartbeat and display it on the monitor.
Doctors check the mother’s weight routinely at every prenatal visit. If the mother’s weight gain is not as expected, it could indicate a problem with the baby’s growth.
It is a test where a needle is inserted into the uterus through the mother’s abdominal skin to draw a small quantity of amniotic fluid. This fluidis then tested to check for chromosomal abnormalities or infections that can lead to fetal growth restriction.
If the healthcare provider determines that the baby’s growth has stopped or is at risk, then you may have to deliver the baby early. The baby will have to remain in the hospital until the body temperature becomes regulated and they can breathe on their own and feed normally.
Although this condition can occur in a perfectly healthy mother, there are certain things to do to reduce the risk. Some of the preventive methods include:
● Not missing prenatal appointments helps detect problems early and treat them.
● Be aware of the baby’s movements so that you can call the doctor for any changes.
● Eat healthy foods to keep the baby nourished.
● Get enough rest.
● Stop smoking, alcohol and drugs.
Understanding FGR is crucial to ensuring the best outcome for the mother and the baby. Knowing the causes, risks, and diagnosis can help detect FGR early and take appropriate measures.
Ultrasound is one of the most common diagnostic tests for fetal growth restriction.
Poor placenta function is one of the most common causes of fetal growth restriction. Other causes include mother’s health problems like advanced diabetes, high blood pressure, heart disease, etc.
It is a condition where the baby does not grow to the average weight during pregnancy as per the gestational age.
FGR is classified into two types: symmetrical and asymmetrical fetal growth restriction.
