Ventricular index (VI) and anterior horn width (AHW) have been determined in neonates (Levene, ArchDisChild 1981, Davies, ArchDisChildFetalNeonatalEd 2000). However, especially data for immature infants are based on small numbers. References ranges for AHW after 34 weeks were extrapolated. No VI and AHW reference values have yet been established for preterm infants at term.
Aim To establish normal values for VI and AHW of lateral ventricles in neonates (GA 24–42 wks) at birth and to determine normal reference ranges at term equivalent age.
Methods A prospective study involving neonates admitted to our Neonatology unit between February 2006 and April 2007, without cerebral pathology. Cranial ultrasound scans were performed within 72 hours after birth, weekly until discharge and at term equivalent age. Dimensions of the lateral ventricles were measured.
Results 351 measurements were performed at varying gestational ages, 80 measurements were done at term equivalent age. There was an agreement with established reference ranges for infants with a GA<33 wks; however the AHW for infants >33 wks were different from the reference ranges extrapolated. Furthermore, the AHW at term differed from the values of full term infants (p⩽0.05).
Conclusion Reference ranges of children with GA<33 wks cannot be extrapolated to a population with a GA>33 weeks. This study continues to establish new reference ranges for this group of infants. Furthermore, values established in full term infants should not be used as reference values for preterm infants at term, due to differences in intrauterine and postnatal development of the brain.