LAUSR

Objectives Growth faltering in relation to the WHO reference is common in the first 2 years of life in South Asia. Stunting, defined as an attained height/length-for-age (H/LA) < -2 Z, is limited in its ability to capture this dynamic process. Our aims were to (1) reveal distributions of growth faltering by age in a cohort of preschool Nepali children, and (2) propose a definition of growth faltering that represents early or continued deviated growth that precedes a child reaching < -2 H/LAZ. Methods We conducted a mixed longitudinal study in 21 wards of 7 randomly selected sub-districts across the Tarai (plains) of Nepal. Mid-year anthropometry was measured annually from 2013-2016 in children < 71 months (mo) of age. Children with paired data over a ∼1-year interval contributed to any of 6 age groups: < 6 mo [n = 645], 6-11 mo [n = 998], 12-23 mo [n = 744], 24-35 mo [n = 691], 36-47 mo [n = 730] and 48-59 mo [n = 637], reflecting age at the outset of the interval. Sex-specific, annualized growth velocities and incidence rates of growth faltering were calculated for each age. Growth faltering was provisionally defined as an annualized decrement (-△) in H/LA of >0.5 Z, corresponding to a ∼ >1 cm/year slower rate of linear growth than an estimated median velocity on the WHO referent growth curve for children < 6 months at the outset. A -0.5 △H/LAZ cutoff was applied to all ages. Results Annualized △H/LAZ [mean (SD)] was -1.3 (1.2), -0.8 (1.2), -0.3(0.8), 0.0 (0.7), 0.1(0.6), 0.1 (0.5) at each age specified above. Incidence of growth faltering was 79.8%, 66.3%, 40.4%, 11.7%, 4.9%, 2.1% at each respective age. Among infants < 6 mo whose initial LAZ was -1 < x < + 1 (excluding extrema), a △LAZ of < -0.5 or >0 (acceleration) was observed in 85.8% and 3.6%, respectively. Conclusions Growth faltering, expressed as an annualized decrement in HAZ >0.5 likely reflects biologically relevant deceleration before children reach < -2 H/LAZ. Two-thirds to 80% of infants in the Tarai of Nepal exhibit growth faltering the year after assessment. By 36 months and older, linear growth, parallels the WHO median attained HA on average, with < 5% appearing to falter, an age at which WHO growth velocity standard curves are lacking. Funding Sources The study was funded by USAID via a subaward from Tufts University under the Feed the Future Innovation Lab for Nutrition. Additional assistance was received from Sight and Life and the Gates Foundation.