Cerebellar growth in normal fetuses of multiple gestations

OBJECTIVE: The purpose of this study was to compare the cerebellar growth in twin and triplet gestations with cerebellar growth in singleton pregnancies. METHODOLOGY: An ultrasound study was conducted in a population of normal pregnant women with singleton, twin and triplet gestations. Routine ultrasound examinations were performed in healthy pregnant women: 951 women with singleton pregnancies; 151 with twin gestations; and 28 with triplet gestations. Although multiple biometric parameters were measured throughout the course of pregnancy, in this study a single measurement (the last measurement before delivery) of the transverse cerebellar diameter (TCD) was used from each patient for statistical analysis. Growth of the TCD was determined in the multiple gestations and compared with growth in singleton pregnancies. RESULTS: A statistically significant relationship was found between TCD and gestational age in all three groups (singleton, twin A and B, and triplets) respectively: R2 = 0.963; R2 = 0.980; R2 = 0.977. No statistical difference was found between the three sets of normative measurements. CONCLUSIONS: There was no significant difference observed in cerebellar growth among singleton and multiple gestations. Therefore, nomograms previously established for singleton pregnancies may be useful to assess growth in multifetal pregnancies.