An intrauterine device (IUD) is a T-shaped plastic device that is inserted into the uterus to prevent pregnancy. IUDs have been used for many years to prevent pregnancy. In the past, there were problems with some IUDs due to design flaws and use in women at risk for sexually transmitted infections. Changes in IUD design and careful patient selection have made the IUD an extremely safe form of birth control.
Two Types of IUD are Currently Available:
Progestin Releasing IUDs: Mirena, Skyla, 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. It is approved for contraception for up to 5 years (3 years in the case of Skyla).
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 also be used to provide intrauterine progestin for hormone replacement after menopause.
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 approved for up to 10 years for contraception.
How Does It Work?
The main effect of the IUD is to prevent the union of sperm and egg to prohibit conception. While it is possible that an IUD could prevent the embedding of a fertilized egg into the uterine wall, this is not considered the mechanism of preventing pregnancy, as the egg should not be fertilized with a functioning IUD in place.
Effectiveness for Contraception
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). This is a slightly lower failure rate than surgical sterilization. For women who attempt pregnancy after an IUD is removed, fertility returns to baseline for the individual immediately after removal.
What are Risks and Side Effects?
Risks associated with an IUD include: (1) inadvertent pregnancy; (2) tubal pregnancy – treatment of which may require surgery and may involve the removal of the fallopian tube; (3) pelvic infection – which may cause tubal scarring, infertility or result in need for surgery, possibly including hysterectomy if infection is severe; (4) perforation of the uterine wall – which may require surgery to remove the IUD; (5) if a pregnancy occurs with an IUD in place, it may result in miscarriage; and (6) expelling the IUD through the cervix.
Side effects associated with the IUD may include lower abdominal cramping and/or irregular bleeding. In some cases, though not commonly, a progestin releasing IUD may cause side effects due to the progestin being released in very small amounts into the general circulation. This could cause acne, mood changes, or bloating in some women. Generally, the amount of progestin that reaches general circulation is negligible and does not cause these systemic side effects. the progestin releasing IUD is considered a local uterine treatment.
Who Should Consider an IUD?
The best candidates for IUD use for contraception are women with a normal uterus and low risk for a sexually transmitted disease (long-term, steady relationship with one partner with no history of infection). Any woman who has multiple partners or a partner with outside sexual relationships is at increased risk of acquiring sexually transmitted diseases and should not use an IUD. It is generally recommended to wait until after having at least one child before using an IUD because women who have not yet given birth generally have higher rates of expelling IUDs and may have more cramping during IUD use. However, not having given birth is not an absolute contra-indication to use of the IUD. Some women with no children are good candidates. This should be discussed with your physician.
Women with the following conditions are advised not to use an IUD: (1) previous ectopic pregnancy; (2) history of pelvic inflammatory disease or PID; (3) congenital malformation of the uterus; (4) large fibroids, or fibroids of any size that distort the uterine cavity; (5) active liver disease or liver tumors (Mirena only); (6) allergy to levonorgestrel (Mirena), polyethylene or copper (7) known or suspected breast cancer (Mirena)(8) recent post-partum or post-abortion infection of the uterus; (9) Leukemia, AIDS or other conditions that predispose to infection.
How Should I Prepare for IUD Insertion?
Prior to insertion, you should avoid intercourse for 2 weeks before your appointment. Take a medication for cramping (800 mg ibuprofen or 2 Aleve tablets) about 30 minutes before you arrive for your appointment. An IUD can be placed during your menstrual cycle or post-partum when the cervix is softer and slightly dilated; however, it can be placed at any time during your cycle.
What Should I Expect at My Appointment for IUD Insertion?
The process of having an IUD inserted usually takes only about 5 minutes. The IUD is placed using a special applicator that is introduced through the cervix into the uterus. During the procedure, most women feel cramping, which can be reduced by taking ibuprofen before the procedure. After insertion, a string at the end of the IUD will extend through the cervix but should not bother you or your partner. Patients who have an IUD insertion in our facility will undergo a pelvic ultrasound immediately afterward, thus assuring correct placement of the IUD within the uterine cavity. The IUD may take up to 2-4 weeks to become effective. Use a second method of contraception (condoms, birth control pills, Nuvaring, etc.) for one month 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. Twenty percent of women stop having periods altogether after one year of use. Paragard, the copper-containing IUD, may cause heavier bleeding or cramping with your menstrual period. This is likely to get better with time and can be relieved with ibuprofen.
When Should I Call My Doctor?
If at any time you develop fever or chills with pelvic pain or tenderness, severe cramping, or unusual vaginal bleeding, contact your doctor to evaluate for a possible pelvic infection or other complication. The IUD should only be removed by a doctor. Removal is usually a simple office procedure.