Intrauterine Growth Restriction: Definition and Classification

Intrauterine Growth Restriction (IUGR) refers to a condition in which a fetus fails to achieve expected growth potential during pregnancy. It is associated with increased risks of perinatal morbidity and mortality.

Definition

IUGR is defined as fetal growth below the 10th percentile for gestational age. This condition is diagnosed using ultrasound measurements, particularly estimated fetal weight (EFW) and abdominal circumference.

Classification

Symmetric IUGR

Characterized by proportional reduction in fetal size affecting all parameters equally, often caused by early pregnancy insults such as genetic disorders or intrauterine infections.

Asymmetric IUGR

Results in disproportionate fetal growth, typically with a normal head size but reduced abdominal circumference. This is often due to placental insufficiency occurring in later pregnancy.

Causes

• Maternal factors: Hypertension, malnutrition, smoking, drug abuse
• Placental factors: Insufficient blood flow, placental abruption
• Fetal factors: Chromosomal abnormalities, congenital infections

Diagnosis

Diagnosis of IUGR involves serial ultrasound assessments to monitor fetal growth, Doppler studies for placental blood flow evaluation, and fetal heart rate monitoring.

Management

Management includes addressing underlying causes, close fetal monitoring, and consideration for early delivery if fetal distress is detected.

Conclusion

IUGR remains a significant concern in obstetrics. Timely diagnosis and intervention are crucial to improving pregnancy outcomes.