We evaluated maternal intake of SDG (secoisolariciresinol diglucoside), a compound from flaxseed, and flaxseed oil+SDG on biochemical and hormonal parameters of dams and male and female offspring during lactation. Dams were fed a standard diet (C); diet added 40 mg of SDG/100g diet (SDG) or diet added 40 mg of SDG/100g diet and 7% of flaxseed oil (OLSDG). SDG and OLSDG dams showed hyperprolactinemia. The OLSDG milk had lower lactose and protein, while the SDG milk had lower protein on the 14th day of lactation. At 14 days, OLSDG male and female pups showed lower body mass, SDG and OLSDG male pups had hypoprolactinemia and lower body fat mass, but higher visceral fat mass (VFM) and hypertriglyceridemia. At 21 days, male SDG and OLSDG presented hypotriglyceridemia. At 14 days, SDG and OLSDG female offspring showed higher serum 17-β estradiol (E2); OLSDG presented hypercholesterolemia and SDG presented hypertriglyceridemia. At 21 days, SDG and OLSDG female pups showed hypotriglyceridemia and OLSDG shower lower E2. Both maternal treatments changes maternal metabolism as well as hormonal and biochemical parameters of the offspring, which are gender-dependent. Maternal hyperprolactinemia may act as an imprint factor responsible for the hormonal and metabolic changes observed in the pups.