IUDs
Intrauterine Devices
An intrauterine device (IUD) is a small, T-shaped contraceptive device (containing either copper or hormone progesterone) inserted into the uterus to prevent pregnancy. It is long-acting, reversible, and highly effective.
Types of IUDs
Copper IUD (Non-hormonal)
Example: CuT 380A (ParaGard)
Mechanism: Copper ions are spermicidal; they create an inflammatory reaction in the endometrium, preventing fertilization and implantation.
Duration: 10–12 years
Efficacy: >99%
Cost (India): ₹300–₹500 in government settings; private sector ₹1,000–₹3,000
Hormonal IUD (Levonorgestrel-releasing)
Examples: Mirena, Kyleena, Skyla
Mechanism: Releases levonorgestrel (LNG) locally; thickens cervical mucus, inhibits sperm, and thins endometrium.
Duration: 3–5 years
Efficacy: >99%
Cost (India): ₹4,000–₹15,000 depending on brand and setting
MECHANISM OF ACTION
Copper IUD (Cu-IUD) – Non-Hormonal
A. Spermicidal Effect
Copper ions released from the IUD into the uterine cavity are toxic to sperm. These ions inhibit sperm motility and capacitation (the physiological changes sperm must undergo to fertilize an egg), impairing their ability to reach and fertilize the ovum.
B. Sterile Inflammatory Reaction
The IUD induces a local inflammatory response in the endometrium. This response involves infiltration of leukocytes, macrophages, and cytokines (e.g., interleukins, prostaglandins). These immune cells attack sperm and prevent fertilization by phagocytosis and degradation of sperm.
C. Endometrial Changes
The inflammatory reaction alters the endometrial lining, making it less receptive to implantation (though this is a secondary mechanism). Inhibition of implantation is not the primary method but may contribute if fertilization occurs.
Key Point: Copper IUDs do not prevent ovulation – they act before fertilization, mainly by affecting sperm.
Hormonal IUD (Levonorgestrel-Releasing IUD) – LNG-IUD
Hormonal IUDs release levonorgestrel, a progestin, at a controlled rate into the uterus. The contraceptive effects are local, not systemic.
A. Thickening of Cervical Mucus
Levonorgestrel causes the cervical mucus to become viscous and impenetrable to sperm. This prevents sperm from entering the uterine cavity and reaching the ovum.
B. Endometrial Suppression
LNG causes the endometrium to become atrophic and thin. This inhibits implantation if fertilization occurs. Histologically, the endometrium shows glandular atrophy and reduced expression of implantation markers (e.g., integrins, LIF).
C. Inhibition of Sperm Function
Progestins impair sperm motility and function in the uterus and fallopian tubes. They reduce sperm capacitation and viability, similar to copper but through hormonal modulation.
D. Ovulation Suppression (Partial)
In some users, especially with higher-dose devices like Mirena, ovulation may be partially or occasionally suppressed. However, ovulation continues in most users, unlike combined oral contraceptives.
Procedure
Consent to be taken after explaining procedure and risks.
Timing: Best inserted during menses (to ensure non-pregnancy and ease of insertion).
Steps: Bimanual exam is done to assess the size and position of uterus Speculum is inserted and vagina and cervix is cleaned with betadine. Uterine length is assessed with a sound. The cervix is held with a tenaculum. Insertion is done with a no touch technique (the IUD is removed from sterile package and inserted under sterile condition).
Follow-up: 4–6 weeks to confirm placement.
Advantages and disadvantages
Advantages
Highly effective and long-acting.
Reversible and quick return to fertility- fertility returns immediately once the device is removed.
Low maintenance (no daily attention)-once inserted, there is no maintenance required in the form of daily contraception.
Cost-effective over time-IUDS are available at nominal fee under government scheme, and no additional cost after initial insertion.
Hormonal IUDs - in addition to contraceptive effect, IUD's can reduce menstrual bleeding and cramps.
Disadvantages
Insertion requires trained personnel and may be painful- unlike other contraceptive methods, IUD's are inserted into the uterine cavity and this needs a medical professional to do the same. Also when the insertion can be painful for some, but can be managed with oral or IV analgesic.
Risk of expulsion or perforation (rare)-the IUD's is perceived as foreign object and hence the uterus contracts to expel it. Hence there is high chances of displacement. Insertion should be done by an experienced healthcare professional in a sterile setting to reduce complications.
May cause spotting/irregular bleeding in first few months- this comes down or stops with in 2-3 months. In case continued bleeding over months, the devices needs to be removed.
Copper IUD: Can increase bleeding and cramps
Hormonal IUD: May cause hormonal side effects (e.g., acne, breast tenderness)
Indications
Suitable for women or couples who desire long-term, reversible contraception.
Women who cannot use estrogen especially with medical conditions (e.g., clotting disorders, smokers >35 years).
Women with heavy menses (for hormonal IUDs)-Progesterone in hormonal IUD help with reducing excessive/abnormal uterine bleeding.
Suitable postpartum after 6 weeks or immediate post-placental in some settings (especially in govt).
Contraindications (WHO MEC Category 3/4)
Active pelvic infection (PID, cervicitis).
Undiagnosed abnormal uterine bleeding- excessive bleeding where the underlying reason has not be found.
Distorted uterine cavity (e.g., fibroids)- Change in size and shape of uterine cavity makes it difficult to insert and also may increase chances of perforation/expulsion.
Copper allergy or Wilson’s disease (for copper IUD)- this may lead to life threatening allergic reactions.
Efficacy
IUD Type Failure Rate (per 100 women/year)
Copper IUD 0.6–0.8% Hormonal IUD 0.2–0.4%
Special Considerations
Postpartum contraception: Can be inserted within 10 minutes of placental delivery. These are recommended in setup where the couple has completed family, but low compliance is expected.
Emergency contraception: Copper IUD effective if inserted within 5 days of unprotected sex and it prevents fertilization and implantation.
Adolescent use: Safe and effective; ACOG and WHO support use in nulliparous women. This is advantages for women/adolescents where compliances with daily pills is low.
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