Nomogram of the cerebellar vermis height at birth in small-for-gestational-age neonates

Aim: To establish a nomogram of the height of the cerebellar vermis at birth in small-for-gestational-age neonates. Methods: Eighty-five consecutively born healthy singletons who were small for gestational age were enrolled in a cross-sectional observational study. The height of the cerebellar vermis was measured by ultrasonography in the midsagittal plane. Reference intervals for the vermian height at 5th, 50th and 95th centiles were estimated at any week of gestational age using a mean and standard deviation model based on least squares polynomial regression. Results: All attempts at obtaining neonatal vermian height were successful. Mean (standard deviation) maternal age was 29.6 (4.7) years; median parity was 1 (range, 1-3). No difference was found between males and females for the vermian height (mean difference [95% confidence interval], -0.03 [-0.16; 0.10] cm). Mean vermian height (in cm) against gestational age (in weeks) was suitably modelled by a quadratic-cubic polynomial (r2 = 0.790, p < 0.0001) as 0.712 + 0.00129 × gestational age2 - 0.0000053 × gestational age3 (SD = -1.009 + 0.0504 × gestational age -0.000014 × gestational age3). Conclusion: A nomogram of the height of the cerebellar vermis at birth against gestational age was established for use in small-for-gestational-age neonates.