Aim: To determine the effects of repeated antenatal corticosteroids on size at birth and later growth and development in Very Preterm (<33 weeks) singleton infants. Design: Prospective regional cohort study (n=664). Exclusions: maternal preeclampsia(n=215), no information on steroid use (n=23). Factors Examined: demographic/obstetric history, size at birth, a/n steroids grouped as none(G0, n=233), one (G1, n=93), two (G2, n=76) or three plus courses (G3, n=24), size at 3 years, Stanford Binet IQ test results at 3 yrs. Results: Significantly more infants had birthweight <10% in G2 and G3 (G0=14.6%, G1=10.8%, G2=19.7%, G3=33.3%). Multivariate analysis showed a progressive reduction in birthweight and head circumference with increasing steroid courses. Infants in G3 had a reduction of 122g and 0.87 cm compared to G0. Steroid use did not affect birth length, growth parameters at three years, disability or IQ outcomes. Conclusions: Multiple courses of antenatal steroids are associated with significant reductions in birthweight and head circumference. These factors have the potential to affect long term outcomes though an independent long term effect was not evident in this cohort.