Expecting a large baby

On top of the fear of giving birth, expecting a large baby worries many mothers. In most cases, it is simply a lovely chubby baby on the way, and there is nothing to be concerned about. However, there are times when the predicted birth weight is quite significant, and this is referred to as foetal macrosomia.

More information in this article!

Expecting a large baby: when do we talk about foetal macrosomia?

First of all, it is important to understand that the birth weight given is an estimate, which means there is an inherent margin of error. That said, when the foetus's weight and size curve starts to accelerate significantly, healthcare professionals may flag the risk of foetal macrosomia. This diagnosis affects 5% of births, and is confirmed when the baby weighs more than 4,000g at birth.

However, some babies weigh around 4kg when they arrive in the world with no complications whatsoever — neither for the child nor for the mother. It is therefore important to discuss your specific situation with your doctor.

What are the risks of expecting a large baby?

Expecting a large baby can be an anxious time for the mother. After all, this "big baby" will need to come out! Certain risks therefore increase with this diagnosis:

• Postpartum haemorrhage for the mother
• Uterine rupture
• Post-partum infection
• Cervico-vaginal lacerations
• Shoulder dystocia in the newborn

Some of these risks can be life-threatening for both mother and child, so it is absolutely essential to be well supported and monitored throughout.

But what are the causes of foetal macrosomia?

• Gestational diabetes
• Heredity
• Maternal obesity or significant weight gain during pregnancy
• Mother's age over 35
• Going beyond the due date

And what about the birth itself?

If foetal macrosomia is confirmed, your doctor will discuss several options with you.

For example, inducing labour from week 39, which still allows for the possibility of a vaginal birth. Alternatively, a caesarean section can be planned to avoid any risk.