The effects of birth weight discordance and prematurity on twin neonatal outcome

The purpose of this study was to determine the effect of birth weight discordance (BWD) and prematurity on twin neonatal outcome by measuring Apgar scores and blood glucose concentrations at birth.

This was a retrospective cross-sectional study. All twins born at NY Methodist Hospital between January 1998 and December 2001 were eligible. Excluded were fetal deaths, maternal systemic disease, maternal infections, major neonatal malformations, neonates with birth weight < 500 g and multiple gestation greater than 2. BWD was defined as intrapair difference in birth weight expressed as percentage of the larger twin greater than 20% and prematurity as gestation of less than 37 weeks. Hypoglycemia was defined as blood glucose concentration < 40 mg/dl.

There were 75 (48%) preterm and 80 (52%) term twin pairs. Nineteen (12%) of the preterm and 15 (9.6%) of the term showed BWD. Mean Apgar scores at 1 and 5 minutes were higher for the term twins as expected. Neither prematurity nor hypoglycemia was present predominantly in BWD twins. Twelve of the preterm and six of the term BWD twins showed evidence of hypoglycemia.

Hypoglycemia in the early hours of postnatal life is relatively common in preterm BWD twins. Blood glucose measurement using reagent strips is an efficient way of monitoring blood glucose concentrations in these infants.