Low dose of betamethasone throughout the whole course of pregnancy and fetal growth: a clinical study.

AIM To assess the eventual influence of low dose betamethasone throughout pregnancy on fetal growth. PATIENTS AND METHODS 320 patients - admitted to the Section of Obstetrics and Gynecology of Ferrara University from January 2005 to December 2010 - were subdivided in two groups: 160 patients affected by recurrent spontaneous abortion (Group A), treated by low dose of betamethasone (0.5 mg/daily) throughout pregnancy for preventive purposes, 160 patients with physiological pregnancy as control group (Group B). Primary measured outcomes were neonatal biometric parameters such as birth weight, head circumference and neonatal length. Unpaired t-test was used to compare the neonatal biometric parameters. RESULTS Birth weight, length and circumference head resulted significantly lower in groups treated by GCs. However, excluding bias as pregnancy complicated by diseases, which could affect fetal growth, biometric neonatal parameters were not different between two groups. Furthermore, analyzing the distribution of the value of birth weight we observed that in the group A there were 44 newborns with a weight even higher than fiftieth percentile. CONCLUSIONS Betamethasone seems not to influence fetal growth. Our analysis demonstrates that fetal growth is influenced by several factors, therefore, homogeneous study population is essential to have convincing results.