Macrocephaly is when a baby has a bigger than average head with a head circumference that is greater than the 98th percentile. According to the fetalmedicine.org macrocephaly is actually pretty common (1 in 100 births) and most often not a sign of a serious problem. It is more common in boys than girls at a rate of 4 to 1. In most cases, having a big head is genetic or inherited, so if one or both baby's parent has a big head, the baby is more likely to have a large head.



In some cases if the baby has a big head it might be a sign of a medical or developmental condition, which is why a doctor will measure the baby's head diameter and circumference during the second trimester screening ultrasound. It is important to know if the baby has a big head in order to monitor the health and development, because it may impact labor and childbirth. A baby with a big head can definitely impact childbirth, increasing the risk of labor complications, assisted delivery, and C-section.



While the thought of giving birth to a big-headed baby might be terrifying to moms-to-be, having a big head actually might be a good thing. Research has found that babies with big heads might actually be smarter and more likely to earn a college degree.