title: Timing and trajectories of fetal growth related to cognitive development in childhood.
abstract: The authors investigated timing and trajectories of fetal growth in relation to childhood development in the National Institute of Child Health and Human Development-Scandinavian Study of Successive Small-for-Gestational Age Births (1986-1988) (n = 1,059). Fetal size was assessed by ultrasound at 17, 25, and 33 gestational weeks and at birth. Bayley Scales of Infant Development and the Wechsler Preschool and Primary Scale of Intelligence-Revised tests were conducted at ages 1 and 5 years, respectively, producing mental and psychomotor development indexes and verbal and performance intelligence quotients. Relative fetal size was calculated as a standard deviation score at each data point; growth trajectories were explored with longitudinal mixture models. Fetal size at 17, 25, and 33 weeks was positively associated with mental development index; larger size at 33 weeks and at birth was associated with higher verbal intelligence quotient scores (2.61, 95% confidence interval: 1.06, 4.15 and 1.90, 95% confidence interval: 0.67, 3.13 increase per 1 standard deviation score, respectively); findings were similar for performance intelligence quotient. Seven trajectories were identified; scores were lower for "small" and "medium-to-small" trajectories than for "medium" and "big" (representing normal size) trajectories: mental development index (P < 0.01), performance intelligence quotient (P < 0.001), and verbal intelligence quotient (P < 0.001). Overall, larger fetal size in the second and third trimesters was positively associated with childhood development. Fetal growth trajectories may matter beyond birth.
authors.affiliation: School of Public Health, University of California, Los Angeles, P.O. Box 951772, Los Angeles, CA 90095-1772, USA. ovehren@ucla.edu
authors.forename: Ondine S
authors.initials: OS
authors.lastname: von Ehrenstein
authors.forename: Rafael T
authors.initials: RT
authors.lastname: Mikolajczyk
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
mesh_terms: D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D005260:Female; D047109:Fetal Development / Q000502:physiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age / Q000502:physiology; D007361:Intelligence Tests; D007804:Language Development; D008297:Male; D011247:Pregnancy; D014888:Wechsler Scales