In WHO "Road to Health" chart, upper and lower limit of represents:

Ans. b. 50 percentile for boys and 3 percentile for girls (Ref: Park 23/e p545, 20/e p547-548)In WHO "Road to Health" chart, upper limit of represents 50th percentile for boys and lower limit represents 3rd percentile for girls.WHO-Home Based Growth ChartWHO growth chart has 2 reference curvesQ:Upper Reference Curve (URC): 50th percentile for boysQLower Reference Curve (LRC): 3rd percentile for girlsQRoad to HealthSpace between two growth curves (weight channel).It includes zone of normality for most populations, i.e. 95% of healthy normal children used as a reference fall in this areaQWHO reference curves are based onQ: NCHS Standards (National Centre for Health Statistics, USA)The 3rd percentile (LRC) corresponds to approximately 2 SD below the median of weight-for-age reference value (URC)QGrowth ChartsThe growth or "read to health" chart (first designed by David Morely and later modified by WHO) is a visible display of the child's physical growth and development.Growth chart is generally plotted between: Weight and AgeQIt is designed primarily for longitudinal follow-up (growth monitoring) of a child, so that changes overtime can be interpreted.The purpose of the chart is early identification of growth failure so that action can be taken to prevent severe malnutrition.Changes in weight are the most sensitive indicators of growth and nutrition status in young children.Growth chart provides information on* Identification and registration* Birth date and birth weight* Chronological age* Weight-for-age* Developmental milestones* History of sibling health* Immunization procedures* Introduction of supplementary foods* Episodes of sickness* Child spacing (Contraceptive/ family planning* methods used)* Reasons for special care