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FGR can happen for different reasons. Sometimes it’s related to your health, the placenta, or how nutrients and oxygen reach your baby. You might be asked to go for additional scans or check-ups so the doctor can track your baby’s development.
If you are told your baby has FGR, it’s natural to feel anxious. But knowing about it helps you and your doctor plan ahead. You might be advised to rest more, eat well, or even deliver the baby early if needed. Every case is different, and with the right care, many babies with this condition do well after birth.
What is Foetal Growth Restriction?
Foetal growth restriction is a condition where a baby does not grow at the expected rate in the womb, resulting in a smaller-than-normal size for their gestational age. This is identified when the baby’s estimated weight is below the 10th percentile for their age, meaning they are smaller than 90 per cent of babies at the same stage of pregnancy.You might hear FGR referred to alongside the term “small for gestational age” (SGA), but they’re not quite the same. FGR specifically involves a pathological condition that affects growth in the womb, while SGA refers to a baby below the 10th percentile who may be constitutionally small without any health problem.
Types of Foetal Growth Restriction
FGR is classified into two main types based on the timing and characteristics of the growth restriction. Each type has its causes and implications for your baby’s development.Symmetrical Foetal Growth Restriction
Symmetrical FGR usually begins early in pregnancy during the first trimester. It is often linked to factors that affect the baby’s overall growth from the start, such as genetic abnormalities, chromosomal disorders or severe maternal malnutrition. Infections like toxoplasmosis contracted early in pregnancy can also play a role in causing this type of FGR.
Asymmetrical Foetal Growth Restriction
Causes of Foetal Growth Restriction
FGR can arise from issues related to the mother, foetus, or placenta, and these factors often overlap. Some of the potential causes are:- Carrying twins or triplets.
- Chronic health conditions like high blood pressure, diabetes, or an autoimmune disorder.
- Smoking, alcohol consumption, or recreational drug use.
- Advanced maternal age or a history of FGR in previous pregnancies.
- Genetic abnormalities in the foetus, such as chromosomal conditions like trisomy 13 (Edwards syndrome) or trisomy 18 (Patau syndrome).
- Have an infection like rubella, syphilis, cytomegalovirus (CMV), or toxoplasmosis.
- Kidney disease.
Symptoms of Foetal Growth Restriction
Most people don’t notice any symptoms that the baby is small for its gestational age. You might feel that your belly or the baby isn’t growing as expected. However, only your healthcare professional can diagnose foetal growth restriction.Although a baby with FGR may show certain signs after birth:
- Low birth weight
- Lower body temperature
- Low blood sugar levels
- High levels of red blood cells
- Difficulty fighting infections
How Foetal Growth Restriction is Diagnosed
Diagnosing FGR begins with routine prenatal check-ups. Your doctor may notice that your fundal height, which measures the distance from your pubic bone to the top of your uterus, does not align with your baby’s gestational age. If this measurement is off by more than 3 centimetres, an ultrasound is usually recommended.During the ultrasound, your doctor will measure your baby’s head, abdomen, and femur to estimate their weight and compare it to growth standards. Doppler velocimetry is used to check blood flow in the umbilical artery. This helps determine if your baby’s growth is truly restricted due to placental issues or if they are simply naturally small.
Amniocentesis is another prenatal procedure that can assist in diagnosing FGR, as it helps in diagnosing the cause of this condition. A small amount of amniotic fluid is carefully extracted from the amniotic sac surrounding your baby using a thin needle guided by ultrasound. This fluid contains foetal cells and other substances that can be analysed to identify potential causes of FGR. Amniocentesis allows doctors to perform genetic testing, such as karyotyping, to detect chromosomal abnormalities or genetic conditions that might contribute to this condition.
Managing Foetal Growth Restriction
Managing FGR focuses on monitoring your baby closely to decide the safest time for delivery. Your doctors weigh the risks of prematurity against the dangers of remaining in the womb.Mild FGR refers to cases where the estimated foetal weight is between the 3rd and 10th percentile without additional risk factors. Its severe form includes cases with estimated foetal weight below the 3rd percentile.
Key management strategies include:
- Ultrasounds every 3 to 4 weeks to track growth and amniotic fluid levels, plus Doppler studies to check blood flow.
- Nonstress tests or biophysical profiles, often starting at 32 weeks or earlier if complications arise.
- Mild FGR delivery may be planned between 37 and 39 weeks. Severe FGR cases involving absent or reversed umbilical artery blood flow may require delivery as early as 30 to 34 weeks. In such situations, a caesarean section is usually recommended due to the baby's reduced ability to handle the stress of labour.
- If delivery is needed before 33 weeks, corticosteroids may be given to help your baby’s lungs mature. Magnesium sulfate may be used before 32 weeks for brain protection.
Potential Complications of Foetal Growth Restriction
FGR can lead to immediate and long-term challenges for your baby. Complications include:Short-Term Issues
- Low blood sugar
- Trouble staying warm
- Breathing difficulties
- Infections
- Prematurity-related problems like respiratory distress syndrome
Long-Term Risks
- Developmental delays
- Learning difficulties
- Behavioural issues
- Increased chances of obesity, heart disease, diabetes, and kidney problems later in life
Preventing Foetal Growth Restriction
Not all cases of FGR can be prevented, but you can take steps to lower your risk. A few of the preventive measures are:- Avoid smoking, alcohol, and recreational drugs, as they can impair placental function.
- Eat a balanced diet and aim for appropriate weight gain during pregnancy to support your baby’s growth.
- Work with your healthcare professional to control conditions like high blood pressure or diabetes.
Managing FGR involves a collaborative effort from your healthcare team to ensure the best care for you and your baby. For more complex cases, a maternal-foetal medicine specialist may be involved to provide advanced care. Open communication with your team is crucial. Share any concerns and ask questions to stay informed about your care plan.
FAQs on Foetal Growth Restriction
- Can foetal growth restriction be treated during pregnancy?
There is no cure, but it can be managed with regular monitoring. Doctors may suggest rest, a healthy diet, and, in some cases, early delivery. - Is foetal growth restriction the same as being small for gestational age?
No. While both involve babies smaller than expected, FGR is linked to a medical condition affecting growth. SGA babies may simply be naturally small but healthy.
