The progestin intrauterine contraceptive device is called the intrauterine system (IUS). It releases low doses of progestin over a period of three to seven years, to prevent pregnancy by multiple mechanisms.

Advantages

Use of the IUS has several advantages such as:

• It is a long-acting method
• It is independent of sexual activity
• Does not interfere with intercourse
• It does not require male partner participation
• It has a high efficacy of over 99 percent
• Provides a very low dose of progestogen
• Maintains normal libido
• It is completely reversible
• Fertility returns quickly after discontinuation
• It can be used for emergency contraception
• It can be used by women who require progestin-only methods, such as those above 35 years, or those who smoke heavily below this age, or have risk factors for arterial or venous thromboembolic disease
• It can be used by lactating mothers
• It is suitable for women who are on certain antibiotics or anticonvulsants which induce hepatic metabolism of estrogen and progesterone, because it is not ingested but absorbed through the endometrium

Non-contraceptive benefits

• It can alleviate several menstrual-related disorders including:
  • menorrhagia
  • dysmenorrhea
  • endometriosis
  • iron-deficiency anemia
  • uterine fibroids
  • endometrial hyperplasia
• Reduces the risk of ovarian cancer and endometrial cancer
• Lower risk of pelvic inflammatory disease
• Lower overall risk of ectopic pregnancy than women not on contraception
• It is useful in treating women on hormone replacement by delivering a constant low supply of progestogen
• Can be used as an alternative to hysterectomy in women with menorrhagia or certain other indications

Disadvantages

The use of the IUS is associated with some drawbacks:

• Menstrual disturbances are universal, and most women develop amenorrhea within six months to a year
• Self-limiting follicular cysts may develop in the first few cycles
• Other women complain of spotting, especially during the first few months
• Expulsion may happen, especially in nulliparous and during the first year, or if inserted just after an abortion or a delivery – the overall risk being 5 percent, and the time being mostly during the menstrual period
• Perforation may occur in 0.2 percent of women, though it is rarely symptomatic
• Initial slightly higher risk of uterine infection if the woman is prone to sexually transmitted infections (STIs) – this may be averted by pre-testing for gonorrhea, chlamydia, and any other organism the woman wishes to be tested for. Treatment of pelvic infection does not require removal of the IUS.
  • hormonal side-effects such as:
  • fluid retention
  • nausea
  • headaches
  • breast tenderness

Serious side effects

Breast cancer risk is slightly increased in women who have used the IUS, including both ductal and lobular types of breast carcinoma. If pregnancy occurs, ectopic gestation is more likely due to the effect on the tubes and the endometrium

Contraindications

The use of the IUS is contraindicated in women suffering from any of the following:

• Current breast cancer (within the last five years) – this is because breast carcinomas are hormonally sensitive
• Fibroids of excessive size
• Untreated uterine or pelvic infection – this could worsen with introduction of the IUS

References

1. http://www.nhs.uk/Conditions/contraception-guide/Pages/ius-intrauterine-system.aspx
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2724187/
3. https://www.ncbi.nlm.nih.gov/pubmed/26243443
4. https://medlineplus.gov/druginfo/meds/a613047.html

Further Reading

• All Contraception Content
• Advantages and Disadvantages of the Contraceptive Patch
• Advantages and Disadvantages of the Contraceptive Implant
• Advantages and Disadvantages of the Contraceptive Vaginal Ring
• Do Contraceptive Injections Affect Bones?

Written by

Dr. Liji Thomas

Dr. Liji Thomas is an OB-GYN, who graduated from the Government Medical College, University of Calicut, Kerala, in 2001. Liji practiced as a full-time consultant in obstetrics/gynecology in a private hospital for a few years following her graduation. She has counseled hundreds of patients facing issues from pregnancy-related problems and infertility, and has been in charge of over 2,000 deliveries, striving always to achieve a normal delivery rather than operative.