While most mothers look forward to welcoming big, healthy babies into the world, delivering larger-than-average infants can pose risks both to the mother and the child.

What is considered a “big” baby?

A newborn weighing more than 8 pounds 13 ounces or 4,000 grams is considered to be a larger-than-average or “macrosomic” baby. While big babies account for around 10% of all births, their size can create complications during delivery.

The Risks for Mother

A woman delivering a bigger-than-average baby is at risk of prolonged labor, tears, and vaginal injury. In fact, mothers of macrosomic babies tend to have a higher rate of cesarean deliveries due to obstructed labor.

Additionally, delivering a larger-than-average baby can lead to postpartum hemorrhage, the severe loss of blood after birth, which can require a blood transfusion.

Women who experience this complication are also at higher risk for developing anemia and lower blood volume.

The Risks for Baby

Bigger babies are at risk for various health issues, such as shoulder dystocia, a birth complication that causes the baby’s shoulders to get stuck in the birth canal, which can cause nerve damage or bone fractures in the baby.

Also, larger babies are more likely to suffer from birth-related hypoglycemia or low blood sugar levels.

They can also have trouble breathing after being born due to underdeveloped lungs, that were not fully compressed during delivery, leading to respiratory distress syndrome.

Causes of Big Babies

While genetics plays a role in determining a baby’s size at birth, there are other factors that increase the likelihood of delivering a bigger baby:.

Maternal obesity: Women who are overweight or obese can increase their risk of delivering a larger-than-average baby due to factors such as elevated glucose levels and limited glucose regulation
Gestational diabetes: When a mother has gestational diabetes, abnormal glucose levels can create a larger baby. Insulin helps control sugar levels, and if a mother has gestational diabetes, her baby may produce more insulin as a result, leading to increased weight gain.
Polyhydramnios: This is a condition in which the amniotic fluid surrounding the baby during pregnancy exceeds the normal volume, which can stretch the uterus and potentially lead to a bigger baby at birth.
Prior macrosomic delivery: Women who have previously delivered a larger-than-average baby are more likely to have another big baby in the future.

Prevention

While delivering a big baby is not entirely preventable, there are things women can do to reduce the risk of complications:.

Maintain a healthy weight and lifestyle before and during pregnancy
Test for gestational diabetes early on in the pregnancy, normally around 20 weeks.
Monitor glucose levels during pregnancy for women with diagnosed gestational diabetes.
Discuss the risks of having a big baby with the treating gynecologist or obstetrician and the preferred method of delivery.
Have regular prenatal checkups to monitor the baby’s growth and development.