Suspected big baby: a difficult clinical problem in obstetrics

Area of Science:

• Obstetrics and Gynecology
• Fetal Medicine
• Neonatal Health

Background:

• Large for gestational age (LGA) fetuses, also known as macrosomic fetuses, present ongoing management difficulties in obstetrics.
• Accurate diagnosis of macrosomia remains a significant clinical challenge.

Purpose of the Study:

• To review the clinical challenges and management strategies for large for gestational age fetuses.
• To provide a comprehensive overview from the perspectives of primary care providers, patients, and obstetricians.

Main Methods:

• A literature search was conducted, primarily utilizing the PubMed database (including Medline).
• The clinical problem of macrosomia was analyzed from multiple stakeholder viewpoints.

Main Results:

• Macrosomia is defined as fetal weight above the 90th percentile, >4000g or >4500g birth weight, or >+2 standard deviations.
• Diagnostic methods, including palpation, symphysis-fundus measurement, and ultrasound parameters (e.g., biparietal diameter, femur length, abdominal circumference), show limited accuracy.
• Abdominal circumference alone demonstrated similar diagnostic utility compared to combined sonographic measures.

Conclusions:

• Induction of labor is not recommended for non-diabetic pregnancies with suspected macrosomia; awaiting spontaneous delivery or induction after 42 weeks is preferred.
• Cesarean section in non-diabetic pregnancies should be reserved for estimated fetal weight exceeding 5000g to prevent complications like brachial plexus paresis.
• In pregnancies with diabetes mellitus, selective labor induction for suspected macrosomia and cesarean section for estimated fetal weight >4000g are indicated.
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