This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Maternal and child care, Subject name: Social & Preventive Medicine
For a given population, minimum no. of newborns to be examined for calculating percentage of LBW of babies 
Select and explain. 
A. 100 babies, B. 500 babies, C. 1000 babies, D. 10,000 babies
B: 500 babies
Answer: B: 500 babies 
Explanation: Low bih weight (LBW): Bih weight less than 2500grams (2.5 kg) . It includes both pre-term (<37 weeks POG) and full-term (>37 weeks POG) babies. Prevelence of LBW: 15% (World); 18% (India); If cutoff for LBW is reduced to 2.0 kg, expected prevelence of LBW inn India will be 5.5% LBW is regardless of gestational age. Depending on the population, the percentage of LBW be based on measurements of atleast 500 babies. Goal for LBW in National Health Policy 1983: Reduce LBW to <10% by 2000. Ref: Park 22th edition Pgno: 495