Developmental outcome of isolated fetal macrocephaly

To evaluate the neurodevelopmental outcome of children with prenatally diagnosed head circumference greater than 2 SD above the mean for gestational age and no associated anomalies detected by ultrasound.

This was a retrospective study of 17 fetuses, diagnosed in the third trimester by ultrasound as having isolated macrocephaly, defined as head circumference greater than 2 SD above the mean for gestational age. We evaluated their performance on a standardized neuropsychological battery at age 2-7 years, and compared them with 17 normocephalic children.

The range of fetal head circumference in the study group was 2.0-2.9 SD. There were no significant differences between the groups in cognitive, language and motor domains. The study group scored significantly worse than the control group on three parameters, reflecting executive functioning, behavior and social-emotional development. Children with familial macrocephaly showed significantly better executive functioning compared with children with non-familial macrocephaly. Multiple linear regression analysis found paternal head circumference to be the only significant variable in positively predicting the cognitive functioning of the child.

The finding in utero of a head circumference 2-3 SD above the mean for gestational age with no associated anomalies does not appear to be a significant risk factor for abnormal long-term neuropsychological development. Our study provides information important for parental counseling prenatally.