What does fetal growth restriction (FGR) mean?

Fetal growth restriction (FGR) is a term used when a fetus's weight is lower than expected for their gestational age, specifically when the estimated weight is below the 10th percentile for fetuses at the same stage [4]. This condition often means the fetus has not grown as required, which may be linked to a deficiency in oxygen or nutrients [3].

Causes of Fetal Growth Restriction

There are many factors that can lead to fetal growth restriction. One of the main causes is the placenta not functioning as efficiently as required, which can be linked to medical conditions such as high blood pressure or preeclampsia [4]. Additionally, certain maternal health problems such as kidney disease, complex heart disease, diabetes, or autoimmune diseases may increase the likelihood of this condition [4].

Lifestyle factors also play an important role. Smoking or using illicit drugs (such as cocaine) during pregnancy are factors that negatively affect fetal growth [4]. Contracting certain infections during pregnancy or the presence of genetic conditions may also hinder the normal development of the fetus [4].

Potential Risks and Complications

The risk of complications depends on how small the fetus is and at what stage of pregnancy the problem was detected. Babies with growth restriction may face a higher risk of preterm birth (before 37 weeks) or may require care in a neonatal unit [4]. In severe cases, the risk of stillbirth increases if placental abruption leads to severe bleeding, or if the baby suffers from oxygen deprivation [3].

Furthermore, babies who did not grow well in the womb may be more susceptible later in life to developing diabetes, congestive heart failure, and high blood pressure [3]. Premature birth associated with problems like preeclampsia can also increase the risk of long-term health issues such as learning difficulties and cerebral palsy [3].

Diagnosis and Medical Monitoring

Regular prenatal check-ups are an essential step for detecting and monitoring the problem. Fetal growth is assessed during medical appointments starting from week 24 by measuring the distance between the pubic bone and the top of the uterus [4]. If the doctor suspects the fetus is small, the mother will be directed to undergo an ultrasound scan to assess growth [4].

For high-risk cases, a uterine artery Doppler scan (usually around week 20) may be requested to measure blood flow to the placenta, as well as an umbilical artery Doppler scan to assess blood flow through the umbilical cord [4]. These detailed examinations, along with fetal heart monitoring, help determine if the fetus requires early delivery for protection [4]. More information on healthy development pathways can be found in our dedicated article on Healthy Fetal Development: Key Stages of Growth and Maternal Support (Arabic).

Emergency Signs and When to Seek Immediate Care

It is essential for the pregnant mother to go to the hospital immediately if she notices any change or decrease in fetal movement [4]. Additionally, urgent medical care should be sought if labor begins unexpectedly, if the water breaks (rupture of the amniotic sac), or in the event of severe vaginal bleeding, especially in the second half of pregnancy, as this can significantly affect fetal growth and safety [4].

Medical references

• What are the risks of preeclampsia & eclampsia to the fetus?
• Having a small baby | RCOG