Birth anthropometry among three Asian ethnic groups in Singapore -- new growth charts

ObjectiveWe analyse birth anthropometry of Asian babies and its socioeconomic exposures, develop gestational age and gender-specific birth anthropometry charts and compare to the widely used Fenton chart. DesignRetrospective observational study. SettingDepartment of Neonatology at the National University Hospital in Singapore. Population or sampleWe report data from 52 220 Chinese, Indian and Malay infants, born from 1991-1997 and from 2010-2017 in Singapore. MethodsThe BW, length and head circumference are each modelled with maternal exposures using general additive model. Anthropometry charts are built using smoothed centile curve and compared with Fenton charts using binomial test. Main outcome measuresBW, head circumference, crown-heel length. ResultsIn contrast to the marked differences in birth anthropometry among these ethnic populations, when exposed to a uniform socioeconomic environment, their intrauterine growth and birth anthropometry were almost identical. From the gestational age specific anthropometric charts, until about late prematurity, Asian growth curves, as derived from our cohort, mirrored that of Fentons; thereafter, Asian babies showed a marked reduction in growth velocity. ConclusionsThese findings suggest comparative slowing of intrauterine growth among Asian babies towards term gestation. This phenomenon may be explained by two possible postulations, firstly, restrictive effects of a smaller uterus of shorter Asian women towards term and secondly, early maturation and senescence of fetoplacental unit among Asians. In clinical practice the new birth anthropometry charts will more accurately identify true fetal growth restriction as well as true postnatal growth failure in preterm infants when applied to the appropriate population. FundingSingapore Population Health Improvement Centre (NMRC/CG/C026/2017_NUHS).