Critical evaluation of Usher's criteria in the assessment of gestational age

Summary 1020 neonates born in the State Zenana Hospital, Jaipur, were studied for evidence of prematurity according to various criteria. The data obtained were recorded and analysed. Special emphasis was laid on the clinical criteria evolved by Usher. The incidence of prematurity, in these 1020 cases, according to the various criteria was determined: Weight up to 2,500 G. 55.6%, crown-heel length less than 47 cm. 52.5%, crown-rump length less than 32 cm. 72.9%, head circumference less than 33 cm. 53.9%, difference between head and chest circumference more than 3 cm. 25.9%, gestational age as evolved by history 16.8%, and clinical criteria of Usheret al. (1966) 13.2%. A comparison of the reliability of the above criteria was made with known gestational age, a definitive criterion. It was found that Usher's criteria were the most reliable for the diagnosis of gestational maturity, next to an accurate history of the gestational age. From the Neonatal Unit, Department of Paediatrics, S.M.S. Medical College, Jaipur.