Surrogate measurements for identifying newborns with low birth weight in a community with predominant non-hospital births.

This cross-sectional study explored the predictive utility of head circumference (HC) and crown-heel length (CHL) as surrogates for identifying birth weight < 2500g (LBW) and < 2000g (VLBW) in an inner-city community with predominant non-hospital births in Lagos, Nigeria. The accuracy of HC and CHL in detecting LBW infants was examined with discriminant analyses and receiver operating characteristic (ROC) curves. Of the 3869 singletons enrolled, 418 (10.8%) weighed < 2500g, 131 (3.4%) weighed < 2000g and 22 (0.6%) weighed < 1500g. Both predictors accurately classified 85.6 percent LBW and 91.9 percent VLBW. The optimum cut-off values for HC and CHL were 32.95cm and 45.95cm for LBW and 31.25cm and 44.85cm for VLBW respectively. HC was consistently more discriminatory than CHL for identifying both categories of LBW. In summary, HC and CHL showed satisfactory discrimination ability to detect LBW/VLBW infants and are potentially valuable as surrogates where birth weights cannot be obtained.