Intrauterine Growth Restriction (IUGR): Causes, Diagnosis & Treatment:
Last Updated! 14th March 2026
Legal Disclaimer:
The articles contained herein are purely for your information and education; they are not in any way to be construed to replace or give medical advice. You should always seek out a physician who is qualified to assist you in any manner during your pregnancy.!
Author!
Dr Humaira Latif
Registered Medical Practitioner
Obstetrician/Gynaecologist
14 plus years of Experience
Table of Contents:
1. What is IUGR
2. Classification Of Intrauterine Growth Restriction.
3. Causes
4.Risk Factors.
5. Symptoms
6. Diagnosis
7. Management.
8. Complications.
9. Prevention
10.When to Seek Medical Care.
11.FAQs
12.To Conclude
13.Related Articles.
14.Refferences.
Introduction!
The main three reasons for having an IUGR baby are:
- Decreased blood flow to the placenta (placental insufficiency).
- Maternal illnesses (e.g., diabetes).
- Fetal abnormalities.
Early detection of the condition through the use of ultrasound and Doppler studies allows for continuous assessment of fetal well being and ultimately helps prevent complications for both the fetus and mo
The Human Growth Index (HGI) was developed by the March of Dimes to account for several factors of fetal growth -including
- Sex.
- Length of pregnancy.
- Health of the fetus.
- Mothers.
In the past 30 years, there has been an increased focus on pregnancy as an important event in the overall adult life course because of the rise in the number of pregnancies that occur as young adults, particularly among lower socioeconomic classes.
This pediatric population represents a unique challenge to clinicians, as they present with a multitude of co-morbidities that affect the course of the pregnancy.
Prevalence:
IUGR occurs in 5%-10% of pregnancies worldwide; making it one of the leading causes of low birth weight and prematurity; as well as causing many significant short term and long-term complications in newborns.
If pregnant women are able to detect the condition early through the use of ultrasound and Doppler studies, they will improve their chances of having a successful pregnancy. Clinicians need to include detailed information regarding IUGR in their medical records so that all parties involved have access to this information for future reference. Since evidence-based medicine is constantly changing, clinicians will want to utilize the same criteria to measure IUGR over time, and that criteria should be documented correctly.
1. What Is Intrauterine Growth Restriction (IUGR)?
Intrauterine growth restriction (IUGR) is a condition in which a fetus grows at a slower rate than expected for its gestational age because of inadequate growth inside the uterus.
IUGR is typically diagnosed when:
• Estimated fetal weight is <10th percentile
• Fetal abdominal circumference is smaller than expected
• Placenta is functioning poorly.
IUGR is not the same as SGA (small for gestational age); although both conditions are associated with small newborns, children who are SGA may be genetically small, but are otherwise perfectly healthy.
2. Classification Of Intrauterine Growth Restriction:
IUGR has two level classifications.
1. Symmetrical IUGR:
In symmetrical IUGR:
a.) The entire fetus is proportionally small.
b.) The size of the head/celephalon and body are equal in proportionate size or proportionally reduced in similar ways.
c.) The fetus has a symmetric IUGR diagnosis when it has been diagnosed at or before approximately 20 weeks gestation.
2. In asymmetrical IUGR:
a.) The size of the head/celephalon will be a normal proportion.
b.) The abdomen will be smaller than the head/celephalon.
c.) Asymmetrical IUGR diagnoses generally occur in the third trimester.
3. Commonly associated causes are due to:
• Chromosomal abnormality.
• Congenital infection.
• Genetic syndrome.
Common causes of asymmetrical growth promotion occur primarily because of the following condition:
- Due to placental insufficiency (placenta not providing adequate levels of oxygen or nutrients).
- Causes of Intrauterine Growth Restriction
- Several maternal, fetal, and placental factors contribute to IUGR.
Maternal Factors:
Maternal health issues are highly correlated to fetal growth restriction, including:
- Hypertension
- Preeclampsia
- Diabetes Mellitus
- Severe Anemia
- Malnutrition
- Smoking
- Alcohol use
- Substance abuse
- Auto-immune disease
- Poor maternal nutrition and chronic illness impairs the supply of oxygen and nutrients to her fetus resulting in restricted growth.
Placental Factors:
The placenta is vital to fetal growth; if the placental function is compromised, the rate of fetal growth will be negatively impacted.
Placental factors include:
- Placental insufficiency
- Placental abruption
- Placenta Previa
- Abnormal placental implantation
- Placental infarction
- The most prevalent cause of asymmetrical IUGR is placental insufficiency.
Fetal Factors:
Certain fetal conditions negatively impact fetal growth. For example:
- Chromosomal disorder
- Congenital anomalies
- Genetic disorder
- Multiple births (twins/triplets)
Infection During Pregnancy:
The development of the fetus can be altered if the mother develops an infection during pregnancy. The most frequent infections that can interfere with fetal development include:
- Cytomegalovirus (CMV)
- Toxoplasmosis
- Rubella
- Syphilis
- Malaria
- Infections may damage fetal tissues and restrict normal fetal growth.
4. Risk Factors of IUGR:
Individuals who have one or more of the following additional factors may be at an increased risk of developing IUGR.
Maternal Risk Factors
- Under age 18
- Over age 35
- Low body mass index
- Poor prenatal care
- Chronic medical conditions
- Smoking
5. Signs and Symptoms of IUGR:
IUGR is commonly asymptomatic, consequently, there may not be any obvious signs of it in the mother. However, during routine prenatal visits, physicians may suspect that the patient has developed IUGR...
Signs That May Indicate IUGR:
- Fundal height not consistent with expected gestational age.
- Decreased fetal activity.
- Maternal weight gain below expected range
- Abnormal size on ultrasound exam
- Regularity of prenatal visits is critical to the early identification of these signs.
6.Diagnosis of Intrauterine Growth Restriction (IUGR):
Early identification of IUGR can lead to improved outcomes for mothers and babies. Physicians have several methods of identifying IUGR.
1. Measurement of Fundal Height:
During routine prenatal visits, the physician measures the distance from the top of the Uterus to the Pubic Bone. If the Fundal height is less than the expected measurement based on the gestation age, further evaluation is indicated.
2. Ultrasound:
Ultrasound is the most reliable method to confirm the diagnosis of IUGR. The following measurements will be taken using ultrasound:
- Biparietal Diameter
- Head Circumference
- Abdominal Circumference
- Femur Length
- Estimated Fetal Weight
- Measurements will be compared to a standard growth curve.
3. Doppler Ultrasound:
Doppler ultrasound evaluates blood flow through fetal vessels and is commonly performed on the following vessels:
- Umbilical Artery
- Middle Cerebral Artery
- Ductus Venosus
- If there is a Doppler abnormality, this suggests that the placenta is unable to nourish the fetus.
4. Non-Stress Test (NST):
The NST evaluates the fetal heart rate and helps to evaluate fetal well-being.
5. Biophysical Profile (BPP):
The BPP is a test that assesses fetal well-being by using ultrasound and fetal heart rate monitoring.
7. Complications Associated with Intrauterine Growth Restriction:
The following are complications associated with intrauterine growth restriction.
IUGR increases the possibility of complications:
1. In Pregnancy
Complications include:
- Preterm birth
- Fetal distress
- Oligohydramnios
- Placental insufficiency
2. In Delivery (Labour
Complications include:
Birth asphyxia
Low birth weight
Emergency c-section
3. After Birth:
Infant with IUGR may develop:
- Hypoglycemia
- Hypothermia
- Respiratory distress
- Developmental delays.
4. As Adult, Infant with IUGR may be at Increased Risk for:
- Hypertension
- Diabetes
- Cardiovascular disease
8. Management of IUGR:
Management of IUGR depends on the following:
- Severity of growth restriction
- Gestational age
- Condition of fetus
1. Close Monitoring by Physician:
Physician will utilize the following modalities for monitoring:
- Serial ultrasounds
- Doppler studies
- Non-stress tests
This monitoring is important for determining when delivery should occur.
2. Maternal Lifestyle Changes:
Pregnant women will receive suggestions on how to improve their health including:
- Improved nutrition
- Stop smoking
- Avoid alcohol
- Adequate rest
- Management of chronic disease
3. Treatment of Maternal Conditions:
Treatment of other conditions which impact growth of fetus (e.g. Hypertension, Diabetes, Infections) can contribute to better fetal growth outcomes.
4. Early Delivery:
If fetus shows signs of distress or is at Severe Growth Restriction, physician may recommend early delivery.
Method of delivery will depend on the following:
- Condition of fetus
- Gestational age
- Cervical readiness
9. Prevention of IUGR:
Not all cases of IUGR can be prevented, but there are steps that can be taken to reduce the risk for future cases.
Preventive Suggestions:
- Attend all regular obstetric appointments
- Maintain balanced maternal nutrition
- Avoid smoking and alcohol use
- Manage any chronic disease
- Treat any infection as soon as it is diagnosed
- Continue to monitor high risk stated pregnancies
10.When to Seek Medical Care:
Pregnant women should seek immediate medical help if they have:
- Fewer fetal movements than usual,
- Significant swelling,
- Severe headaches,
- Bleeding from the vagina,
- Severe pain in their abdomen.
If the mother receives help quickly enough, she may be able to prevent any complications from happening.
11. Questions Answered:
Q(1). Is IUGR harmful for my child?
Yes, if My Little One is left untreated there may be more of a possibility of them being born stillborn, prematurely, or having problems after birth. If you are diagnosed with IUGR soon enough and followed closely, the chance for a positive outcome is much larger.
Q(2). Will my child get bigger after delivery if they have IUGR?
Most babies will be able to catch up to their growth potential after being born with IUGR as long as they are identified early enough and managed correctly.
Q(3). Does IUGR mean that my baby will always have low birth weight?
No. Low birth weight means your baby weighs less than 2.5 kilograms at birth and IUGR means your baby was not able to grow at its optimal rate in utero.
Q(5). Will nutrition help my baby's growth?
Yes. Adequate nutrition of the Mother and proper prenatal care are necessary for a healthy growing baby.
12. To Conclude:
Intrauterine Growth Restriction is a serious condition that requires early detection and careful monitoring along with prompt management. Even though there are additional risks associated with this condition to both the Mother and the baby, recent advancements in obstetrical care along with recently developed means of monitoring the fetus have resulted in much improved outcomes than in the past.
Good nutrition, healthy lifestyle habits, regular prenatal visits, and timely medical attention will yield the best outcome possible for a pregnancy complicated by IUGR.
13.Related Articles:
1. Pregnancy Nutrition Guide.
2. Gestational Diabetes Diet Plan
3. Understanding Preeclampsia in Pregnancy
4. PCOS and Fertility Management
5. Pregnancy Warning Signs Every Woman Should Know
14. References:
1. American College of Obstetricians and Gynecologists (ACOG).
Fetal Growth Restriction (Practice Bulletin No. 227).
Published: February 2021
Link:
This guideline reviews terminology, causes, diagnosis, and management strategies for fetal growth restriction in pregnancy.
2. American College of Obstetricians and Gynecologists.
ACOG Practice Bulletin No. 204: Fetal Growth Restriction.
Published: January 24, 2019
Journal: Obstetrics & Gynecology
This evidence-based guideline discusses clinical evaluation, Doppler monitoring, and management of pregnancies complicated by fetal growth restriction.
3.Society for Maternal-Fetal Medicine (SMFM) and ACOG.
Fetal Growth Restriction Clinical Practice Guideline.
Published: February 2019
The guideline highlights screening methods and the role of umbilical artery Doppler and fetal surveillance in improving pregnancy outcomes.
4.Society of Obstetricians and Gynaecologists of Canada (SOGC).
Guideline No. 442: Fetal Growth Restriction Screening, Diagnosis and Management.
Published: October 2023
This guideline provides updated recommendations for identifying high-risk pregnancies and managing fetal growth restriction using evidence-based clinical frameworks.
5.American College of Obstetricians and Gynecologists.
Fetal Growth Restriction Guideline Summary.
Published: February 2019
The guideline emphasizes the importance of fetal monitoring tools such as non-stress testing and biophysical profiles in managing IUGR pregnancies.
6.American College of Obstetricians and Gynecologists.
ACOG Practice Bulletin No. 134: Fetal Growth Restriction.
Published: May 2013
Journal: Obstetrics & Gynecology
This earlier guideline provides foundational definitions and clinical recommendations for diagnosing and managing IUGR.
Disclaimer:
The articles contained herein are purely for your information and education; they are not in any way to be construed to replace or give medical advice. You should always seek out a physician who is qualified to assist you in any manner during your pregnancy.
Author Background:
Dr. Humaira Latif
Medical Degree: MBBS from Khyber Medical University, Peshawar
Medical Specialty: Obstetrics & Gynecology
Sub-specialty: Ultrasound, with 14+ years of clinical experience
Publisher of Medical Information: Reliable and Evidence-Based
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