Developmental Correlates of Head Circumference at Birth and Two Years in a Cohort of Extremely Low Gestational Age Newborns

Abstract

Objectives-To evaluate the developmental correlates of microcephaly evident at birth and at 2 years in a cohort born at extremely low gestational age.Methods-We assessed development and motor function at 2 years of 958 children born before the 28th week of gestation, comparing those who had microcephaly at birth or 2 years with children with normal head circumference while considering the contribution of neonatal cranial ultrasound lesions.Results-A total of 11% of infants in our sample had microcephaly at 2 years. Microcephaly at 2 years, but not at birth, predicts severe motor and cognitive impairments at 2 years. A total of 71% of children with congenital microcephaly had a normal head circumference at 2 years and had neurodevelopmental outcomes comparable with 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 nearly a third had cerebral palsy. The risks were increased if the child also had cerebral white matter damage on a cranial ultrasound scan obtained 2 years previously.Conclusion-Among extremely low gestational age newborns, microcephaly at 2 years, but not at birth, is associated with motor and cognitive impairment at age 2.Ahead circumference more than 2 standard deviations (SD) below the mean for age defines microcephaly, an indicator of reduced brain volume,1 and a correlate of cognitive and motor dysfunctions.2 -5 Compared with infants born at term, low birth weight and extremely low gestational age newborns (ELGANs) are at increased risk of having microcephaly at birth (congenital microcephaly), as well as subnormal head size evident later in childhood. 2 ,3 ,6 This

Clinical phenotype of the recurrent 1q21.1 copy-number variant

“…We identified a significant inverse association between head size and both verbal IQ and fine motor ability in duplication carriers. Associations between head size and fine motor ability have inconsistently been found in other populations, [28][29][30][31] but this finding highlights a moderately strong relationship between two aspects of the 1q21.1 phenotype and provides an avenue for further examination of the brain abnormalities underlying functioning in individuals with 1q21.1.…”

Outcomes of Extremely Preterm Infants Born to Insulin-Dependent Diabetic Mothers

“…Brain volume is a determinant of head size; however, microcephaly at 2 years, but not at birth, is predictive of severe motor and cognitive impairments. 21,22 Both poor glycemic control and hypertension have previously been associated with preterm delivery among women with type 1 diabetes. [23][24][25][26] Nearly 60% of the women with IBP had hypertension, a majority of whom had chronic hypertension.…”

Clinical importance of hypothyroxinemia in the preterm infant and a discussion of treatment concerns

“…Choosing a treatment efficacy endpoint in addressing THOP CP and low Bayley cognitive scores are closely related outcomes, and both are associated with THOP [2][3][4]6,7,41]. Therefore, we suggest that these forms of neurodevelopmental disability are likely to be influenced by thyroid hormone supplementation in ELGANS.…”

“…Cerebral palsy affects nearly one in eight survivors, and is often accompanied by other major comorbidities [1]. Thus, the major public health problem that improved survival has created is the large population of surviving ELGANs who exhibit combinations of cognitive delay, CP, hearing loss, blindness, mental retardation, or epilepsy [2][3][4][5][6][7][8]. The ELGAN population of more than 25 000 surviving US neonates born annually before 28 completed weeks of gestation did not exist 40 years ago [9].…”