Background: Among the 50,000 VLBW infants born yearly in the U.S., there is an increasing number of multiple gestation birth mainly due to the recent advances in in vitro fertilization. In autopsy studies it has been shown that brains of twins show a delay of 2-3 wks in the development of convolutional markings compared to non-twins(1). Delineation of the regional and temporal characteristics of impaired brain development in such infants would be of major interest.

Study design/Subjects: As part of our study quantifying brain development in preterm infants with 3D-MRI, 14 sets of twins and 9 sets of triplets were studied as part of the total data set of 100 preterm and fullterm newborns. Using 3D-MRI and segmentation, total brain volume was defined and percentages calculated for CSF, myelinated and unmyelinated white matter (WM) and total gray matter (GM).

Results: Initial data from 11 single gestation (SG) and 14 multiple gestation babies (MG) have shown lower volumes of myelinated WM in MG babies compared to the volumes measured in SG. Analysis-of-covariance testing for equality of slopes in the small data set showed a p-value of 0.07. No apparent differences in developmental changes of total GM or CSF were observed.

Conclusion: Initial data evaluation suggests an apparent specific delay in myelin deposition at birth in the brain of multiple gestation babies.