Study finds head circumference better gauge for C-section

Women who receive prenatal care expect their physician to watch for potential issues as their pregnancy progresses. This can include monitoring development of the fetus for triggers that may indicate the need for a cesarean section delivery (C-section) as opposed to traditional vaginal birth. A recent study found that physicians would be able to better predict the need for a C-section by using the fetus’ head circumference, as opposed to estimated birthweight, to guide this decision.

The study, published in the American Journal of Obstetrics & Gynecology, gathered data from two years’ worth of births. The scientists chose to review births that involved one fetus with a 37 to 42-week gestational age. Based on their analysis, they found:

• Large head circumference: Attending physicians delivered 62% of infants with a head circumference in the 95 percentiles or larger through a traditional, vaginal delivery, 16% required unplanned C-section and 11.2% required instrument assistance such as the use of forceps.
• Large birthweight: Doctors delivered 80% of infants with a birthweight in the 95 percentiles or higher through vaginal delivery, 10.2% with unplanned C-section and 3.4% with instrumental assistance.

Based on this data, the scientists concluded a large head size was more likely to predict the need for an unplanned C-section when compared with the infant’s estimated birthweight. Physicians can use this information to discuss the potential need to modify a prospective mother’s birth plan. A physician who fails to discuss a developing fetus’ large head size can put the mother and fetus at an increased risk for injury during the delivery process.