All IUDs are essentially made of polyethylene & impregnated in barium to be radio-opaque.
Two nylon threads are attached to the IUD for the following:
- To indicate that the IUD is in place.
- To facilitate its removal.
- These are no more used.
- Lippes loop was the one commonly used before 1985. It is double S in shape and available in 4 sizes.
Medicated IUDs: All medicated IUDs are supplied in per-sterilized packages.
• Copper IUDs e.g. Cu T-380 or Multiload-250 :
- It is T-shaped with a vertical limb covered by a copper wire. Cu T also contain copper sleeves on the horizontal limbs.
- The exposed surface of copper is 380 mm2 & it releases copper ions at rate of about 60-65 microgram daily.
- It should be changed every 4 years. - Nova-T is a Cu-T IUD in which a silver core is added in the vertical limb to prolong its use up to 6 years.
- It is T-shaped, releasing 65 microgram of progesterone daily.
- It should be changed every 1 year.
- Progesterone is added to minimize the menstrual blood loss.
- Progestasert increases the incidence of tubal pregnancy because progesterone interferes with tubal motility.
• Anti-fibrinolytic agent:
An antifibrinolytic as trasylol is added to the IUD to minimize the menstrual blood loss.
Mode of action
"Not definitely known" the following are possible explanations;
1. Endometrial changes:
- Ulceration at the points of contact with the IUD.
- Edema & congestion of the stroma.
- Foreign body reaction i.e. round cell infiltration.
"These changes interferes with implantation"
2. Increased uterine motility:
The increased prostaglandins leads to expulsion of the zygote.
3. Increased tubal motility:
This causes the ova to reach the uterus before the endometrium ready for implantation.
4. Attraction of macrophages:
This causes phagocytosis of the sperms.
Copper ions released in the uterus inhibit carbonic anhydrase. This renders the endometrium unsuitable for implantation.
6. Progesterone (Progestasert):
It renders the endometrium unsuitable for implantation.
To insert an IUD the following is essential;
1. Selection of IUD users:
• The most suitable:
- Multiparas with regular average or scanty cycles.
- Lactating women.
NB: In nullipara there is higher incidence of pain and expulsion.
These contraindications are detected by history & complete examination
- Congenital uterine anomalies e.g. bicornuate uterus.
- Severe cervical stenosis.
- Pelvic infections whether active or recurrent.
- Undiagnosed genital bleeding.
- Uterine tumor as cancer or fibroid.
- History of ectopic pregnancy.
2. Timing of insertion:
• Post-menstrual to exclude pregnancy.
• At the end of puerperium or 2 weeks after abortion to minimize expulsion.
3. Technique of insertion:
• A volsellum is used to grasp the anterior lip of the cervix.
• A uterine sound is passed to assess the size & direction of the uterus.
One of the following is used;
a. Withdrawal technique: (for Copper-T or progestasert)
- The introducer containing the IUD, is introduced in the uterus up to the fundus. The plunger is passed into the introducer till it reaches the lower end of the IUD.
- The plunger is fixed in place & the introducer is withdrawn on it. This withdrawal results in release of the IUD in the uterus.
- The nylon threads appear in the vagina through the cervix.
b. Pushing technique: (for Lippes loop)
- The introducer containing the IUD, is introduced in the uterus just past the cervix. The plunger is passed into the introducer till it reaches the lower end of the loop.
- The plunger is gently pushed to release the IUD in the uterus.
4. Instructions to the IUD user after insertion:
• Uterine colic, post-insertion spotting & vaginal discharge may occur.
• The first few menses following insertion may be heavier than normal.
• The user should feel the nylon threads after the end of each menses.
• Checkup examination is essential after one month, then annually.
5. Indications of removal:
• Pregnancy is desired.
• Complications as persistent bleeding, pelvic infection or perforation.
• After 34 years for copper IUDs & 1 year for progestasert.
Advantages of IUD include;
- It is cheap & available
- Very effective – at least 99%.
- Does not affect lactation.
- No effect on sexual intercourse.
- Rarely affects future fertility.
- Requires little motivation (It is one decision method unlike the pills).
- Long acting - can stay in place for three or more years.
- Reversible - possible to get pregnant as soon as the IUD is removed.
- Can be easily removed (by any doctor or Family Planning nurse) if you don’t like it or want to get pregnant.
- No-one else needs to know you are using it.
- No evidence of an increased risk of cancer.
- Copper IUDs do not contain any hormones.
- Copper IUDs can also be used to prevent pregnancy after unprotected sexual intercourse (emergency contraception).
- Hormone IUDs release a very small dose of hormone and most women have no side effects from this.