Gynaecology & Obstetrics

Which of the following is the best explanation for the mechanism of the action of the intrauterine device (IUD)?

Hyperperistalsis of the fallopian tubes accelerates oocyte transpo and prevents feilization

A subacute or chronic bacterial endometritis interferes with implantation

Premature endometrial sloughing associated with menorrhagia causes early aboion

A sterile inflammatory response of the endometrium prevents implantation