The intrauterine device (IUD) is a T-shaped plastic device that is inserted into the uterus to prevent pregnancy or to reduce/eliminate menstrual flow. IUDs have been in use for decades as a convenient, safe, and highly effective method of of birth control, and more recently, to manage heavy menstrual periods.
Two Types of IUD are Currently Available:
1. Progestin Releasing IUDs: Liletta, Mirena, Kyleena.
These IUDs contain a progestin (progesterone-like hormone) called levonorgestrel, which is continuously released into the endometrial cavity from the IUD. This type of IUD works by thickening the mucus plug in the cervix (the entrance to the uterus), thus blocking sperm entry and preventing conception. These devices are FDA approved to provide contraception for up to 8 years (5 years in the case of Kyleena).
Because the progestin releasing IUD releases a low continuous dose of a progestin into the uterus, it can decrease menstrual flow and improve some other conditions that typically cause excessive bleeding or uterine pain such as endometriosis, adenomyosis, fibroids, or endometrial hyperplasia. The progestin releasing IUD can serve as both a treatment for menstrual issues and an effective birth control option. It can even be used to provide intrauterine progestin in conjunction with systemic estrogen therapy after menopause.
2. Copper Containing IUD: Paragard (Copper T 380A)
This IUD contains copper, which is released locally into the endometrial cavity. The Paragard IUD reduces sperm motility and function to prevent conception. It is FDA approved for up to 10 years for contraception.
How Does an IUD Work?
The main effect of the IUD is to prevent the union of sperm and egg, thus preventing fertilization and conception.
Effectiveness for Contraception
The IUD is actually superior to tubal sterilization in preventing pregnancy. The reported failure rate of the progestin releasing IUD is 0.1% to 0.7% (1-7 per 1000), for Paragard, 0.6% to 0.8% (6-8 per 1000). Fertility returns immediately after removal of the device.
What are Risks and Side Effects?
Side effects associated with an IUD may include transient cramping and/or irregular spotting. The progestin releasing IUD features a beneficial “side effect” in that it typically reduces menstrual flow significantly; often to the point of eliminating flow. The progestin IUD is considered to have only local (uterine) effects, and the amount of progestin reaching the general circulation is negligible. Thus, hormonal side effects should not occur. Paragard (copper) IUD may increase menstrual flow for some.
Adverse events associated with an IUD are uncommon, and include uterine infection and delayed expulsion of the IUD through the cervix. With blind IUD insertion, uterine perforation would be a small risk. However, with ultrasound guidance provided in our facility, the device’s position is carefully visualized during and after insertion into the uterine cavity, so uterine perforation is not an issue.
What Should I Expect at My Appointment for IUD Insertion?
The process of having an IUD inserted typically takes about 5 minutes. The IUD is placed using a specialized applicator introduced through the cervix into the uterus. During the procedure, most women feel some cramping, which can be reduced by taking ibuprofen before the procedure. After insertion, a thin string at the end of the IUD will extend through the cervix, and this will be trimmed to the perfect length that should not bother you or your partner. Patients who have an IUD insertion in our facility will undergo a pelvic ultrasound, thus assuring correct placement of the IUD within the uterine cavity. The IUD takes 4 weeks to become effective, so it is important to use a second method of contraception (condoms, birth control pills, etc.) for 4 weeks after having the IUD placed.
What Should I Expect AFTER an IUD Insertion?
During the first 3 to 6 months after insertion of a progestin releasing IUD, irregular, light bleeding may occur as the body adjusts to the device. After 6 months of use, approximately 50% of women have only very light spotting, an average of about three days per month. A large percentage of women stop having periods altogether after one year of use.
With the copper IUD, menstrual flow does not cease, but sometimes becomes heavier. For this reason, many women prefer the progestin IUD.