Neonatal mid-upper-arm circumference is a valid proxy for birth-weight.

A survey was carried out on a consecutive sample of 973 newborn babies representative for the city of Ouagadougou to assess the validity of neonatal mid-upper-arm-circumference (MUAC) as an indicator of birth-weight. The optimal cut-off point of neonatal MUAC to differentiate between low (less than 2500 g) and normal (greater than or equal to 2500 g) birth-weight babies was 9.5 cm. High values for sensitivity (91%) and specificity (83%) indicate an excellent validity. A newborn with a MUAC of less than 9.5 cm runs a 23 fold risk of being of low birth-weight (relative risk). The advantages of this simple, locally available and inexpensive indicator, which can be used by trained traditional birth attendants (TBA) and by the mothers themselves as a substitute for birth-weight, are discussed.