TGFβ2 has immunoregulatory properties and is involved in growth, differentiation and repair of neonatal intestinal epithelia. Measurement of TGFβ2 concentrations in human milk varies greatly between mothers, the reasons for which have yet to be explained. Antenatal steroids are routinely used in high-risk pregnancies to accelerate maturation of fetal organ systems. Glucocorticoids are shown to modulate TGFβ2 expression and activity in other systems. The effect of antenatal steroids on human milk cytokines, particularly TGFβ2, is unknown. The purpose of this study was to compare human milk TGFβ2 concentrations in mothers who received antenatal steroids versus an untreated control group. Mothers (n=25) donated human milk samples on postpartum days 1 through 31with gestational ages ranging from 25 to 41 weeks. Information was collected by interview or chart review concerning parity, antenatal steroid use, infant's birthweight, and gestational age. Milk was collected and stored at -20°C. For analysis, human milk samples were thawed and centrifuged at 2500g × 20 min at 4°C. After discarding the fat and cellular components, the aqueous samples were stored at 4°C for analysis the next day. The concentration of acid-activated TGFβ2 in the aqueous compartment of milk was measured using an ELISA (R&D Systems). The mean ± SD concentration of TGFβ2 in control group (n=19) was 9507±7196 (range 831 to 24850) pg/ml human milk. The mean concentration of TGFβ2 in antenatal steroid group (n=16; dose number 1 to many) was 4995±4406 (range 1162 to 17300) pg/ml. The mean concentration of TGFβ2 was 52% less in the antenatal steroid group (p=0.03). Among the 2 groups tested, there was no correlation between gestational age, birthweight, maternal days postpartum or parity and TGFβ2 concentration. In conclusion, this small study shows a significant decrease in human milk TGFβ2 levels in a group of women who received antenatal steroids. Future study to confirm a true effect should focus on a larger sample size of colostrum and early milk with better matching of sample collection times.