Can pregnancy still occur after IUD insertion?
(1) The IUD has fallen out of the uterine cavity without the user noticing, and no alternative contraceptive measures were taken.
(2) The IUD has slipped into the cervical canal. Since the endometrium isn't in contact with the device, it doesn't interfere with fertilized egg implantation.
(3) The IUD size is incompatible with the uterine cavity, or the device is twisted/deformed, rendering it ineffective for contraception.
(4) In rare cases, the uterine lining may not exhibit a corresponding tissue reaction after IUD insertion, or the fertilized egg may not encounter implantation barriers, potentially leading to pregnancy.
An IUD is a foreign object that can stimulate uterine contractions, leading to its expulsion. It is often expelled with menstrual blood, though the woman may not notice its expulsion. Multiple factors contribute to IUD expulsion:
(1) The material, quality, shape, and size of the IUD itself. For example, IUDs with a stem provide better support; though slightly more difficult to insert, they are less prone to expulsion.Plain metal rings and softer-material rings are easier to insert but prone to expulsion. (2) The user's age, number of previous births, and cervical tone also play a role. Generally, younger women, those with fewer births, or lactating women may experience expulsion due to greater uterine muscle elasticity and sensitivity. Women with a lax cervix or uterine prolapse are also at higher risk.
(3) Improper ring selection—too large, too small, or failure to position the ring at the fundus during insertion—can also cause expulsion.