Fertilisation and implantation failure in an oral contraceptive user.

We report the case of a young woman taking a low-dose oral contraceptive (gestodene 0.075mg and ethinylestradiol 0.02mg) in whom we documented by both hormonal assays and sonographic evaluations the occurrence of ovulation, oocyte fertilization and embryo implantation. However, the implantation process did not complete and only a biochemical pregnancy was registered. On the basis of known actions of estroprogestin on endometrium that are not conducive to implantation, it is possible that the pregnancy loss was originated by oral contraceptive's hormonal influence at endometrial level.