Head size at birth in neonates with transposition of great arteries and hypoplastic left heart syndrome.

Objective: Appropriate fetal brain growth depends upon the cerebral blood flow (CBF). Different congenital heart defects (CHDs), due to the difference in anatomy and physiology, alter the intrauterine CBF. Thus, variable brain growth is expected in different CHDs that is reflected by variability in the head circumference (HC) at birth. The present study was carried out to compare the HC of babies born with transposition of great arteries (TGA) and hypoplastic left heart syndrome (HLHS) in comparison to normal control.

Methods: The data on the HC of neonates with TGA and HLHS were extracted from the computer database then compared with the control group. During the period from January 1996 to December 2003, a total of 7396 neonates were admitted, out of which 639 (8.6%) were admitted with the diagnosis of the CHD. After correcting for gestational age and non-availability of HC measurements, 236 infants were excluded. Out of the remaining 403 term appropriate for gestational age (AGA) infants, 46 had TGA while 28 had HLHS. The control group comprised of a total of 74 term AGA infants.

Results: The mean HC for the control group was noted to be 34.4 +/- 1.7 centimeters (cms), 33.7 +/- 1.5 cms for TGA while it was 32.9 +/- 1.3 cms for HLHS. The head size at birth for newborn with HLHS was significantly smaller than the TGA (p=0.03) and control group (p=0.001). Similarly, HC of TGA group was significantly smaller than the control group (p=0.02).

Conclusion: The newborns with TGA and HLHS are found to have significantly small head size at birth. The clinical significance of this finding with respect to the neurodevelopmental outcome and value of early antenatal intervention to repair these defects remains to be evaluated in further studies.