From the second pregnancy a woman is easier to produce milk with which to feed her baby, thanks to the mammary gland is prepared to respond to the hormonal disturbances that precede the gestation, as has discovered a group scientists from Cold Spring Harbor Laboratory (CSHL) in New York (USA).
During pregnancy exceptional changes in the breast secretion of certain hormones and progesterone – and that translates into a massive proliferation of mammary epithelial cells and formation of thousands of ductal structures that allow the production and transport of milk during lactation.
CSHL researchers found that in female mice that had already been pregnant mammary glands expand more quickly, and begin to do it before, that in the case of those who experience the hormones of pregnancy for the first time. As explained by Camila dos Santos, assistant professor in CSHL, this is an example of epigenetic memory wherein loss of DNA methylation mark the areas of the genome that were activated in a previous pregnancy.
This expert noted that in his laboratory aim to investigate how their discovery could be related to the fact that women who become pregnant at age 25 have significantly lower rates of breast cancer than those with children at higher ages or do not, and thus check if any of the changes that have been detected in their study may prevent the occurrence of this type of tumor.