Understanding foetal macrosomia: causes and possible management

Foetal macrosomia is a medical term that describes a situation in which a baby's weight at term exceeds certain reference values. This condition can lead to complications during childbirth, for both the baby and the mother. In this article, we will explore the causes of foetal macrosomia, the associated risks, and how to manage this situation.

Causes and risk factors of foetal macrosomia

Several factors may contribute to the occurrence of foetal macrosomia. To fully understand this situation, it is worth first examining the various potential causes, including:

Maternal diabetes: pregnant women with diabetes (pre-existing or gestational) are at an increased risk of giving birth to a baby who weighs more than average.

Maternal obesity: excess weight in the mother increases the likelihood of delivering a baby with a high birth weight.

Prolonged pregnancy: if the pregnancy extends beyond the usual 40 weeks, this can lead to excess foetal growth.

Family history: in some families, giving birth to larger-than-average babies is part of the genetic make-up.

The baby's sex: boys are more likely to display foetal macrosomia than girls.

Possible consequences for the baby and the mother

The risks associated with foetal macrosomia concern not only the newborn, but also the mother.

Here are some possible consequences:

For the mother

Difficulties during labour: due to the baby's significant weight, a vaginal delivery without complications can sometimes be challenging.

Increased likelihood of a caesarean section: if the medical team considers that a vaginal delivery carries too many risks, they may opt for a caesarean section to deliver the baby safely.

Postpartum bleeding: after delivering a larger baby, the risk of bleeding for the mother is increased.

Perineal tears: during the delivery of a macrosomic baby, the perineal tissues may tear and require surgical repair.

For the baby

Complications during delivery: due to its size, the baby may sustain physical trauma, such as a fractured arm or collarbone.

Perinatal asphyxia: this refers to a lack of oxygen in the newborn, causing brain distress and sometimes serious long-term effects.

Neonatal hypoglycaemia: macrosomic babies born to diabetic mothers may develop low blood sugar after birth, which must be closely monitored and treated if necessary.

Increased risk of obesity and diabetes in adulthood: individuals who experienced foetal macrosomia are more likely to develop these health problems later in life.

Managing foetal macrosomia during pregnancy

Preventing foetal macrosomia relies above all on good care for the pregnant woman. This includes:

Regular medical monitoring: in order to detect and prevent complications, it is essential for the mother to attend the recommended antenatal appointments.

Managing maternal diabetes: women with diabetes must maintain rigorous blood sugar control during pregnancy. This involves a balanced diet, monitoring weight gain, and adjusting medication if necessary.

Maintaining regular physical activity: unless medically contraindicated, moderate exercise during pregnancy is recommended to help limit the risk of foetal macrosomia.

Avoiding risky behaviours: alongside a healthy lifestyle, it is essential to avoid alcohol, tobacco, and drugs during pregnancy.

Managing foetal macrosomia during labour

In the event of suspected or confirmed foetal macrosomia, the medical team will take various factors into account when deciding on the best approach to delivery. These will include:

The baby's estimated size: if the macrosomia is significant, the doctors may opt for a planned caesarean section.

The type of labour and delivery: in some cases, doctors may attempt a vaginal delivery whilst closely monitoring for signs of dystocia or complications.

Obstetric history: if the mother has previously given birth to a larger baby without complications, it is more likely that a vaginal delivery will be attempted.

The presence of other complications or risk factors: if other elements threaten the health of the mother or baby, a specific decision will be made taking all factors into account.

In summary, foetal macrosomia is a condition that warrants particular attention in order to limit the possible consequences for the mother and newborn. Prevention relies primarily on regular medical monitoring and holistic care for the pregnant woman. When macrosomia is identified, doctors will choose the most appropriate delivery method according to the circumstances.