Hypoxic risk in twins assessed by serum creatinine kinase brain isoenzyme measurement.

A marked intrapair discordance in placentas and in many body and organ measurements are risk factors influencing perinatal mortality and morbidity in twins. Asphyxia is the single most important perinatal cause of neurologic morbidity in newborn infants. The higher hypoxic risk for the second twin arises, however, from conclusions based on studies that did not consider the new diagnostic possibility of using blood measurements of the brain-type isoenzyme of creatine kinase (CK-BB) as a marker of perinatal asphyxia. CK-BB levels were measured in cord blood of 60 preterm infants (mean birth weight 1670 +/- 390 g, and mean gestational age 33 +/- 1.9 weeks) born of twin gestation in the last 3 years. The mean CK-BB values were 48 +/- 40 U/l versus 29 +/- 31 U/l (p less than 0.5). Skilful antepartum and perinatal care are the keys for optimal management of both babies, as demonstrated by similar CK-BB values obtained in their cord-blood specimens after birth.