Developmental and motor function at age 2 years of 958 children born before the 28^th week of gestation were assessed at Boston and Harvard Universities and other centers, comparing those with microcephaly at birth or 2 years with children with normal head circumference. A total of 11% of infants in the sample had microcephaly at 2 years. Microcephaly at 2 years, but not at birth, was predictive of severe motor and cognitive impairments at 2 years. Of children with congenital microcephaly, 71% had normal head circumference at 2 years and similar neurodevelopmental outcomes to those with normal head circumference at birth and 2 years. Among children with microcephaly at 2 years, more than half had a Mental Developmental Index <70, and almost a third had cerebral palsy, rates 3 times greater than among children without microcephaly. Neonatal cranial ultrasound showing white matter damage increased risk of poor neurodevelopmental outcome. [1]

COMMENT. Extremely low gestational age newborns (in the ELGANs epidemiological study) are at risk of neurodevelopmental dysfunction and autism [2]. Microcephaly at 2 years, but not at birth, is associated with cognitive and motor impairment at age 2. Almost three-fourths of ELGANs with congenital microcephaly outgrow the problem by age 2 years. Congenital microcephaly is only a risk factor for CP or cognitive impairment if the microcephaly persists.