Intrauterine Contraception Devices
The intrauterine device (IUD) is a small T-shaped plastic device that either contains hormones or is wrapped in copper and is inserted into the uterus by a trained medical professional(1). A plastic string attached to the device hangs through the cervix and into the vagina for monthly checks and for removal(1).
The hormonal IUD (Mirena) releases levonorgestrel (a form of progesterone). It is effective at preventing pregnancy with inhibition of egg fertilization by damaging or killing sperm, affecting the uterine lining not allowing it to thicken, which is where the fertilized egg would implant and grow, and by making the mucus in the cervix thick and sticky so sperm Is not able to migrate through(2). It also decreases menstrual bleeding and cramping(2).
The copper IUD (Paragard) has a copper wire wrapped around the T shaped IUD and is effective because copper is toxic to sperm. Aside from its toxic affect it promotes fluid production by the uterus and fallopian tubes that contains WBC, copper ions, enzymes, and prostaglandins that kill the sperm(2).
Although the IUD should not directly cause pain, in the instance a malpositioned IUD or an IUD that was inserted at the time of an undetected genital infection, pelvic and abdominal region pain can be prominent(1). Hormonal IUDs can also cause breast tenderness, mood swings, headaches, and acne in the first few months after insertion(1). Copper IUDs can increase vaginal bleeding and cramping during menses.
Perforation of the uterus is rare but is a risk of insertion(2). Expulsion of the IUD from the uterus to the vagina occurs in 2-10% of females within the first year(2). IUDs are effective at protecting from pregnancy but do not protect against sexually transmitted infections(2). If you have a patient complaining of pelvic pain who recently had an IUD inserted be cognizant of the other signs and symptoms and perform a more thorough screening.
After a thorough subjective patient history and sexual history if you feel that the patient could have indirect pelvic pain resultant of their IUD referral is required. The patient will need follow up diagnostic testing such as an Ultrasound to detect the actual cause and rule out malpositioning of the device, pregnancy, and any STIs or other infections.