Large for gestational age (LGA) infants are those whose birth weight exceeds the 90th percentile (P90) for their gestational age. Newborns with a birth weight greater than 4 kg are referred to as macrosomic infants.
Etiology
Physiological Factors
LGA infants may result from factors such as large parental body size or excessive maternal food intake during pregnancy, including high consumption of proteins and other nutrients.
Pathological Factors
These include:
- Maternal diabetes.
- Hyperinsulinism caused by islet cell hyperplasia.
- Hemolysis and hypoxia-related fetal edema due to conditions such as Rh incompatibility, hemoglobinopathy, or severe intrauterine hemolytic anemia.
- Congenital heart diseases, such as transposition of the great arteries.
- Beckwith-Wiedemann syndrome.
Clinical Manifestations
Labor-Related Injuries
Due to their larger size, LGA infants are prone to complications during delivery. These complications include asphyxia, intracranial hemorrhage, and various birth traumas such as brachial plexus injury, phrenic nerve injury, clavicular fracture, liver rupture, and compression injuries to the head and face.
Clinical Manifestations of Underlying Disorders
Rh incompatibility may lead to severe hyperbilirubinemia, anemia, edema, and hepatosplenomegaly.
Transposition of the great arteries often presents with tachypnea, cyanosis, and hypoxemia.
Infants of diabetic mothers are frequently associated with preterm birth, hypoglycemia, respiratory distress syndrome, hyperbilirubinemia, and polycythemia.
Hyperinsulinism caused by islet cell hyperplasia may result in persistent hyperinsulinemia and refractory hypoglycemia.
Beckwith-Wiedemann syndrome is characterized by distinct facial features (including exophthalmos, macroglossia, and facial vascular nevi), ear fissures, organomegaly, umbilical hernia, and hypoglycemia.
Long-Term Complications
LGA infants have a significantly higher risk of developing obesity, type 2 diabetes, and other components of metabolic syndrome compared to infants appropriate for gestational age.
Treatment
Efforts should be made to reduce risks associated with difficult labor and asphyxia.
Prompt management of underlying disorders and their associated complications is vital.
Prevention
Improved prenatal care should focus on balanced nutrition during pregnancy to prevent excessive energy and protein intake.
Maternal pregnancy-related complications, such as diabetes, should be actively managed and prevented where possible.
Enhanced fetal monitoring during pregnancy is essential to identify risk factors early and allow for timely interventions.