Fetal Macrosomia

Fetal macrosomia is a condition in which a baby grows significantly larger than average during pregnancy. It is usually defined as a birth weight greater than 4,000 to 4,500 grams, regardless of gestational age. Fetal macrosomia increases the risk of complications during labor and delivery for both the mother and the baby. The condition is commonly associated with maternal diabetes but can occur even in the absence of known risk factors.

Symptoms

Fetal macrosomia itself does not cause noticeable symptoms during pregnancy. However, healthcare providers may suspect the condition based on certain findings:

• Fundal height measuring larger than expected for gestational age

• Excess amniotic fluid detected on ultrasound

• Difficulty estimating fetal size during physical examination

The diagnosis is often suspected before birth and confirmed after delivery.

Causes

Fetal macrosomia occurs when excess nutrients, particularly glucose, are delivered to the fetus, stimulating increased growth. Several factors can contribute to this process:

• Maternal diabetes, including gestational diabetes

• Poorly controlled blood sugar levels during pregnancy

• Excessive maternal weight gain

• Genetic factors influencing fetal size

• Prolonged pregnancy beyond the due date

These factors may act alone or in combination.

Risk Factors

Several maternal and pregnancy-related factors increase the risk of fetal macrosomia:

• Gestational or preexisting diabetes

• Obesity or high body mass index before pregnancy

• Excessive weight gain during pregnancy

• History of delivering a large baby

• Post-term pregnancy

• Male fetus

• Maternal age over 35

The likelihood increases with multiple risk factors.

Complications

Fetal macrosomia can lead to complications during and after delivery:

• Prolonged or difficult labor

• Shoulder dystocia during vaginal delivery

• Increased risk of cesarean delivery

• Birth injuries such as fractures or nerve damage

• Postpartum hemorrhage

• Low blood sugar levels in the newborn

• Increased risk of obesity and metabolic disorders later in life

Careful monitoring helps reduce the risk of serious complications.

Prevention

Fetal macrosomia cannot always be prevented, but certain steps may lower risk:

• Maintaining healthy blood sugar levels during pregnancy

• Following recommended guidelines for pregnancy weight gain

• Eating a balanced, nutrient-rich diet

• Engaging in regular, pregnancy-safe physical activity

• Attending regular prenatal checkups for monitoring fetal growth

Early identification and proper prenatal care play a key role in reducing complications associated with fetal macrosomia.