Previous studies have shown that Cheviot embryos are shorter than Suffolk embryos at d 19 of gestation, even when uterine capacity is not a limiting factor for embryo growth, evidence of the role the maternal uterine environment plays in embryo development. We determined if there were differences in the circulating concentrations of progesterone (P4), IGF-1, insulin and adiponectin between Cheviot and Suffolk dams during early gestation. Ewes (Cheviot, n = 8 and Suffolk, n = 6; 58.6 vs. 78.2 kg live weight, P < 0.05, with no differences in body condition score) were inseminated (d 0) laparoscopically with fresh semen from rams of the same breed. Blood samples were taken from the ewes every other day from d 0 to 21. Hormone concentrations were analyzed by repeated measures including using the fixed effects of maternal breed, day of sampling and their interaction; the covariance structure was first-order autoregressive AR(1), and for P4 concentrations the number of corpora lutea was used as a covariable. Cheviot dams had a higher P4 concentration than Suffolk dams from d 6 to 21 of pregnancy (6.82 ± 0.31 vs. 5.84 ± 0.33 ng/mL, P < 0.05) and P4 was also affected by ovulation rate (P < 0.001) as animals presenting with 2 corpora lutea had greater P4 than those with a single ovulation. No effect of ovulation rate was found for the rest of the hormones. Insulin concentrations were also greater in Cheviot dams compared with Suffolk dams (27.0 ± 2.0 vs. 20.4 ± 2.3 µUI/ mL, P < 0.05), while IGF-I concentrations did not differ among breeds. Suffolk ewes tended to present greater adiponectin concentrations than Cheviot ewes (4.4 ± 1.0 vs. 2.1 ± 0.8 ng/mL, P = 0.099). The greater P4 concentration found in Cheviot dams is consistent with their higher insulin concentration, as insulin stimulates granulosa cell P4 production. The opposite profile was found for adiponectin concentration, with the higher levels found in Suffok dams potentially associated with adiponectin inhibition of insulin-induced progesterone secretion by granulosa cells, as has been found in other species. The differences in hormone concentrations according to breed could explain the distinct embryo growth found during early gestation.