IUDs have been known and used for thousands of years in large domestic animals, but only recently have they been used by humans.

Modern IUDs are easily inserted, have a very high effectiveness rate (98-99%), and are well-tolerated by most of the women who use them. Their effectiveness continues for varying lengths of time, depending on the type of IUD.

• The copper releasing PARAGUARD IUD is good for 10 years.
• The hormone releasing Mirena and Liletta IUDs are protective for 8 years.
• Hormone releasing Kyleena IUD works for up to 5 years.
• Hormone releasing Skyla IUD works for up to 3 years.
• An inert IUD, such as the Lippe’s Loop is good forever.

Inert and Copper-containing IUDs tend to make menstrual flows somewhat heavier, crampier and longer, while hormone-containing IUDs tend to make them somewhat lighter, shorter, and less cramp. This may be a consideration in assessing the appropriateness of an IUD for any individual patient.

Infection

With the newer designs, the risk of infection has been significantly reduced. Sooner or later, about 3-5% of IUDs will be removed because of infection. Most of these infections are minor, with mild symptoms of vague pelvic discomfort, painful intercourse and possibly a low-grade fever. The uterus is tender to palpation although the adnexa usually are not. Treatment of such mild infections generally involves prompt removal of the IUD, oral broad spectrum antibiotics and complete resolution of symptoms. Infertility following such mild infections is uncommon.

With the less common, serious infections, a high fever can be found, movement of the cervix causes excruciating discomfort and the adnexa are extremely tender. In addition to prompt removal of the IUD, IV antibiotics are recommended to treat this moderate to severe PID. In these cases, recovery is generally slow (days to weeks) and infertility is a distinct possibility.

Perforation

The overall risk of perforation of the IUD through the uterine wall is about 1 in 1,000. Most of these occur during the insertion of the IUD or shortly thereafter. More common than perforation is the “disappearance” of the IUD string. While such a disappearance may suggest the possibility of perforation, a more likely explanation is that the string has coiled up inside the cervical canal or even inside the uterus.

A truly perforated IUD is usually removed from the abdominal cavity with laparoscopic or open surgery.

Missing IUD String

When confronted with a missing IUD string, most clinicians will gently probe the cervical canal to see if they can tease the string back down through the os. A cotton-tipped applicator or a Pap smear brush works well for this purpose. Once the string is brought down into the vagina (and about 3/4 will be found this way), nothing further needs to be done.

If the string is not inside the cervical canal, then further evaluation and treatment will be needed from an experienced and well-equipped gynecologic consultant. X-ray can confirm that the IUD remains somewhere within the pelvis. Ultrasound can demonstrate the presence of the IUD inside the uterine cavity. For an IUD which is clearly inside the uterine cavity but whose string has retracted into the cavity, a careful judgment must be made.

In some circumstances, the IUD is removed with an IUD hook, D&C or hysteroscopy, and a new once replaced. In other circumstances, it may be appropriate to accept the fact (and the risks) that the string will not be visible, and leave the IUD where it is until the IUD expires before removing it.

Pregnancy

IUDs are very effective at preventing pregnancy, but there is a small failure rate of about 1-2% each year.

If pregnancy occurs, it is important to remove the IUD immediately (the same day if possible). The normal spontaneous miscarriage rate is about 18-20%. For women who conceive despite an IUD, the miscarriage rate is about 25% when the IUD is removed immediately. If the IUD is left in place, the miscarriage rate increases to about 50%, and many of those are septic mid-trimester losses which are particularly unpleasant and which are associated with subsequent infertility in some cases.

If deployed, even the relatively inexperienced health care provider can remove the IUD because: 1) it is simple and easy to do, and 2) delaying removal for several days until a more experienced provider can see the patient risks retraction of the string up inside the uterus, making simple removal impossible. The IUD should first be removed and then the patient moved to a definitive care setting in anticipation of a possible miscarriage.

Ectopic Pregnancy

Should a pregnancy occur despite the presence of an IUD, there is an increased likelihood that it will be an ectopic pregnancy. Instead of the typical rate of about 1-2%, the ectopic pregnancy rate is about 5%. This means that in addition to prompt removal of the IUD, the patient needs a careful evaluation with ultrasound and possibly adjunctive laboratory tests to determine the presence of the pregnancy. Should an ectopic pregnancy be found, medical and/or surgical management is usually undertaken.

In many military settings, such an evaluation may not be possible and medical evacuation should be considered.

Contraindications

Contraindications to IUD use include:

• Known or suspected pregnancy
• Known distortion of the uterine cavity
• PID past or current
• Pregnancy-related infection within the last 3 months
• Known or suspected cervical cancer
• Undiagnosed vaginal bleeding
• Current cervicitis or vaginitis until effectively treated
• Wilson’s disease
• Allergy to copper
• Impaired immune system
• Genital actinomycosis

Insertion of the IUD

An IUD can be inserted at any time, provided the physician is confident that the patient is not currently pregnant. Many physicians prefer to insert the IUD during a normal menstrual flow. This provides some assurance that the patient is not currently pregnant. Second, the cervical canal is already somewhat dilated from the menstrual flow and so the actual IUD insertion is more comfortable for the patient. Third, there is usually a small amount of bleeding following insertion of the IUD which will not be noticed if the patient is currently flowing. The IUD may be inserted between 4-6 weeks postpartum, and can also safely be inserted immediately after delivery (within 3 days of delivery).

Insertion usually causes mild uterine cramping which disappears in a few minutes. Pretreatment with a NSAID can block much of that discomfort.The use of prophylactic antibiotics is an unresolved controversy.

Removal of the IUD

An IUD can be removed at any time, but should be removed in the presence of pelvic infection, pregnancy, abdominal pain of uncertain cause or if the IUD is already partially extruded. Never push a partially extruded IUD back inside the uterus as you will introduce significant bacterial contamination into either the uterus or the abdominal cavity, whichever area you penetrate.

After placing a vaginal speculum, visualize the cervix and the IUD string(s) protruding through the cervical os. Grasp the strings with any convenient instrument (hemostat, dressing forceps, ring forceps, etc.) and pull the IUD straight out with a steady, smooth, slow pull. The IUD, by virtue of its’ pliability, will fold onto itself and slide out. Most patients will feel either no discomfort or minimal uterine cramping during removal. They generally comment that having the IUD removed was not as uncomfortable as having it inserted.