Does Plan B affect Significant Changes in Endometrial Structure or Physiology such to prevent implantation of a fertilized ova?
There are several studies that address this question to determine what changes occur in the endometrial mileau when Plan B (Emergency contraception, morning after pill, day after pill, post coital contraception, day after contraception) is given. Even if significant changes do occur, it really does not mean that Plan B’s affect at other previous steps prior to the ova entering the uterine cavity is not the prime reason or only reason for how Plan B works. Endometrial biopsies were taken 8 to 9 days after Plan B was taken which corresponded to ovulation. The endometrium revealed either minimal or no changes in microscopic appearance or biochemical markers. Another study found diminished amounts of endometrial glycodelin A in a few women who had received Plan B. Since glycodelin A appears to play a role in adhesion of the embryo to the endometrial surface, such an effect could be a mechanism by which Plan B interferes with implantation. However, in this study endometrial glycodelin A was
