Please ask, after taking emergency contraception pills, will it cause ectopic pregnancy?

Patient's question:

Please ask, does taking post-coital emergency contraception pills such as Norlestrin or cause ectopic pregnancy? Thank you

Doctor's answer:

Hello. It generally does not lead to ectopic pregnancy.
Reasons:
(1) Tubal inflammation: Approximately 60% of patients with tubal pregnancy have a history of tubal inflammation. Recurrent chronic tubal inflammation causes adhesions of the tubal mucosal folds, narrowing of the lumen, damage to cilia, or twisting of the fallopian tubes due to inflammation and adhesion with surrounding tissues, impairing normal peristalsis. These factors can hinder the normal movement of the fertilized egg, preventing it from reaching the uterine cavity on time and leading to implantation in the fallopian tube.
(2) Abnormal fallopian tube development or after tubal surgery: Conditions such as excessively long fallopian tubes, absence of mucosal cilia, or reconnection after tubal ligation or tubaloplasty may all cause tubal pregnancy.
(3) Ovum migration: When an ovary on one side releases an egg, it may fertilize and then travel through the uterine cavity or peritoneal cavity to the opposite fallopian tube, a phenomenon known as ovum migration. As the ovum grows during this transit, if it cannot pass through the fallopian tube, it may implant there, resulting in tubal pregnancy.
(4) Women with pelvic endometriosis or those using intrauterine devices (IUDs) may also have an increased risk of tubal pregnancy.