title: Size at birth and early childhood growth in relation to maternal smoking, parity and infant breast-feeding: longitudinal birth cohort study and analysis.
abstract: There is remarkably wide variation in rates of infancy growth, however, its regulation is not well understood. We examined the relationship between maternal smoking, parity, and breast- or bottle-feeding to size at birth and childhood growth between 0 and 5 y in a large representative birth cohort. A total of 1,335 normal infants had weight, length/height, and head circumference measured at birth and on up to 10 occasions to 5 y old. Multilevel modeling (MLwiN) was used to analyze longitudinal growth data. Infants of maternal smokers were symmetrically small at birth (p < 0.0005) compared with infants of nonsmokers, however, showed complete catch-up growth over the first 12 mo. In contrast, infants of primiparous pregnancies were thin at birth (p < 0.0005), showed dramatic catch-up growth, and were heavier and taller than infants of nonprimiparous pregnancies from 12 mo onwards. Breast-fed infants were similar in size at birth than bottle-fed infants, but grew more slowly during infancy. Among infants who showed catch-up growth, males caught up more rapidly than females (p = 0.002). In conclusion, early postnatal growth rates are strongly influenced by a drive to compensate for antenatal restraint or enhancement of fetal growth by maternal-uterine factors. The mechanisms that signal catch-up or catch-down growth are unknown but may involve programming of appetite. The importance of nutrition on early childhood growth is emphasized by the marked difference in growth rates between breast- and bottle-fed infants. The sequence of fetal growth restraint and postnatal catch-up growth may predispose to obesity risk in this contemporary population.
authors.affiliation: Department of Paediatrics, University of Cambridge, Addenbrookes Hospital, Cambridge, UK.
authors.forename: Ken K L
authors.initials: KK
authors.lastname: Ong
authors.forename: Michael A
authors.initials: MA
authors.lastname: Preece
authors.forename: Pauline M
authors.initials: PM
authors.lastname: Emmett
authors.forename: Marion L
authors.initials: ML
authors.lastname: Ahmed
authors.forename: David B
authors.initials: DB
authors.lastname: Dunger
mesh_terms: D001724:Birth Weight; D001827:Body Height; D001835:Body Weight; D001942:Breast Feeding; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006128:Growth; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D008431:Maternal-Fetal Exchange; D010298:Parity; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012727:Sex Characteristics; D012907:Smoking / Q000009:adverse effects*; D006113:United Kingdom