Hormonal intrauterine device


A hormonal intrauterine device, also known as an intrauterine system 'with progestogen and sold under the brand name Mirena' among others, is an intrauterine device that releases a progestogenic hormonal agent such as levonorgestrel into the uterus. It is used for birth control, heavy menstrual periods, and to prevent excessive build of the lining of the uterus in those on estrogen replacement therapy. It is one of the most effective forms of birth control with a one-year failure rate around 0.2%. The device is placed in the uterus and lasts three to eight years. Fertility often returns quickly following removal.
Side effects include irregular periods, benign ovarian cysts, pelvic pain, and depression. Rarely uterine perforation may occur. Use is not recommended during pregnancy but is safe with breastfeeding. The IUD with progestogen is a type of long-acting reversible birth control. It works by thickening the mucus at the opening of the cervix, stopping the buildup of the lining of the uterus, and occasionally preventing ovulation.
The IUD with levonorgestrel was first approved for medical use in 1990 in Finland and in the United States in 2000. It is on the World Health Organization's List of Essential Medicines.

Medical uses

The hormonal IUD is an extremely effective method of birth control, and a 2021 study demonstrated that it may be used for emergency contraception. In addition to birth control, the hormonal IUD is used for prevention and treatment of:
Advantages:
  • Considered one of the most effective forms of reversible birth control
  • Can be used while breastfeeding
  • No preparations needed before sex, though routine checking of the device strings by patient and physician is advised to ensure proper placement remains intact
  • 90% of users who wish to become pregnant do so within 24 months of removal.
  • May experience lighter periods
  • Effective for up to three to eight years
Disadvantages:
  • Irregular periods and spotting between periods often occurs after insertion This usually improves after three to six months.
  • Moderate to severe discomfort may be experienced during insertion procedure, including uterine cramping and back pain.
  • Other potential [|adverse effects] and risks

    Effectiveness

After insertion, Mirena is effective at preventing pregnancy for up to eight years. Kyleena is approved for five years and Skyla is approved for three years.
The hormonal IUD is a long-acting reversible contraceptive, and is considered one of the most effective forms of birth control. The first year failure rate for the hormonal IUD is 0.1-0.2% and the five-year failure rate is 0.7-0.9%. These rates are comparable to tubal sterilization, but unlike sterilization the effects of the hormonal IUD are reversible.
The hormonal IUD is considered to be more effective than other common forms of reversible contraception, such as the birth control pill, because it requires little action by the user after insertion. The effectiveness of other forms of birth control is mitigated by the users themselves. If medication regimens for contraception are not followed precisely, the method becomes less effective. IUDs require no daily, weekly, or monthly regimen, so their typical use failure rate is therefore the same as their perfect use failure rate.
In a 10-year study, the levonorgestrel IUD was found to be as effective as oral medicines for heavy periods; the same proportion of study participants had not had surgery for heavy bleeding and had similar improvements in their quality of life.
In people with complete bicornuate uterus and in need of contraception, two IUDs are generally applied due to lack of evidence of efficacy with only one IUD. Evidence is lacking regarding progestogen IUD usage for menorrhagia in bicornuate uterus, but a case report showed good effect with a single IUD for this purpose.

Breastfeeding

Progestogen-only contraceptives such as an IUD are not believed to affect milk supply or infant growth. However, a study in the Mirena application for FDA approval found a lower continuation of breastfeeding at 75 days in hormonal IUD users versus copper IUD users.
When using Mirena, about 0.1% of the maternal dose of levonorgestrel can be transferred via milk to the
nursed infant.
A six-year study of breastfed infants whose mothers used a levonorgestrel-only method of birth control found the infants had increased risk of respiratory infections and eye infections, though a lower risk of neurological conditions, compared to infants whose mothers used a copper IUD. No longer-term studies have been performed to assess the long-term effects on infants of levonorgestrel in breast milk.
There are conflicting recommendations about use of Mirena while breastfeeding. The U.S. CDC does not recommend any hormonal method as a first choice of contraceptive for [|nursing mothers], although progestin-only methods, such as Mirena, may be used with close follow-up or when the benefits outweigh the risks. The World Health Organization recommends against immediate postpartum insertion, citing increased expulsion rates. It also reports concerns about potential effects on the infant's liver and brain development in the first six weeks postpartum. However, it recommends offering Mirena as a contraceptive option beginning at six weeks postpartum even to nursing women. Planned Parenthood offers Mirena as a contraceptive option for those who are breastfeeding beginning at four weeks postpartum.

Contraindications

A hormonal IUD should not be used by people who:
Insertion of an IUD is acceptable after a dilation and evacuation abortion, but may be associated with a higher expulsion rate. To reduce the risk of infection, insertion of an IUD is not recommended for women that have had a medical abortion but have not yet had an ultrasound to confirm that the abortion was complete, or that have not yet had their first menstruation following the medical abortion.
A full list of contraindications can be found in the WHO Medical Eligibility Criteria for Contraceptive Use and the CDC United States Medical Eligibility Criteria for Contraceptive Use.

Side effects

  • Irregular menstrual pattern: irregular bleeding and spotting is common in the first three to six months of use. After that time periods become shorter and lighter, and 20% of women stop having periods after one year of use. The average user reports 16 days of bleeding or spotting in the first month of use, but this diminishes to about four days at 12 months.
  • Cramping and pain: many women feel discomfort or pain during and immediately after insertion. Some women may have cramping for the first 1–2 weeks after insertion.
  • Expulsion: Sometimes the IUD can slip out of the uterus. This is termed expulsion. Around 5% of IUD users experience expulsion. If this happens a woman is not protected from pregnancy. Expulsion is more common in younger women, women who have not had children, and when an IUD is inserted immediately after childbirth or abortion.
  • Perforation: Very rarely, the IUD can be pushed through the wall of the uterus during insertion. Risk of perforation is mostly determined by the skill of the practitioner performing the insertion. For experienced medical practitioners, the risk of perforation is one per 1,000 insertions or less. With postpartum insertions, perforation of the uterus is more likely to occur when uterine involution is incomplete; involution usually completes by 4–6 weeks postpartum. Special considerations apply to women who plan to [|breastfeed]. If perforation does occur it can damage the internal organs, and in some cases surgery is needed to remove the IUD.
  • Pregnancy complications: Although the risk of pregnancy with an IUD is very small, if one does occur there is an increased risk of serious problems. These include ectopic pregnancy, infection, miscarriage, and early labor and delivery. As many as half the pregnancies that occur in Mirena users may be ectopic. The incidence rate of ectopic pregnancies is approximately one per 1000 users per year. Immediate removal of the IUD is recommended in the case of pregnancy. No pattern of birth defects was found in the 35 babies for whom birth outcomes were available at the time of FDA approval.
  • Infection: The insertion of the IUD does have a small risk of pelvic inflammatory disease. Concurrent infection with gonorrhea or chlamydia at the time of insertion increases the risk of pelvic inflammatory disease. If PID does occur, it will most likely happen within 21 days of insertion. The device itself does not increase the risk of infection.
  • Ovarian cysts: Enlarged follicles have been diagnosed in about 12% of the subjects using a hormonal IUD in studies that use ultrasound to look for cysts, even if asymptomatic. In studies that only evaluate symptomatic cysts, only 4.5% of women complain of any ovarian cysts over 5 or more years of use, and only 0.3% require IUD removal for ovarian cysts. Thus, any issues with ovarian cysts are not of a clinically relevant nature. Most of these follicles are asymptomatic, although some may be accompanied by pelvic pain or dyspareunia. In most cases the enlarged follicles disappear spontaneously after two to three months. Surgical intervention is not usually required.
  • Mental health changes including: nervousness, depressed mood, mood swings
  • Weight gain
  • Headache, migraine
  • Nausea
  • Acne
  • Excessive hairiness
  • Lower abdominal or back pain
  • Decreased libido
  • Itching, redness or swelling of the vagina
  • Vaginal discharge
  • Breast pain, tenderness
  • Edema
  • Abdominal distension
  • Cervicitis
  • Bacterial vaginosis
  • May affect glucose tolerance
  • May experience a change in vision or contact lens tolerance
  • May deplete vitamin B1 which can affect energy, mood, and nervous system functioning
  • A "lost coil" occurs when the thread cannot be felt by a woman on routine checking and is not seen on speculum examination. Various thread collector devices or simple forceps may then be used to try to grasp the device through the cervix. In the rare cases when this is unsuccessful, an ultrasound scan may be arranged to check the position of the coil and exclude its perforation through into the abdominal cavity or its unrecognised previous expulsion.