Intrauterine Device (IUD)

An intrauterine device (IUD) is a small, T-shaped contraceptive device placed inside the uterus. There are two main types: copper and hormonal. The copper IUD contains no hormones. Copper slows sperm and prevents fertilization, the joining of sperm and egg. At higher levels, copper may also change the endometrium, the uterine lining, in ways that affect implantation. Its main action still comes first, before sperm and egg meet.

The hormonal IUD releases a synthetic progestin, levonorgestrel, into the uterus. It thickens cervical mucus and thins the endometrium. It may also stop ovulation in some users, mostly in the first year. Whether it also acts after sperm and egg meet is in scientific dispute. That question bears on informed consent for couples who regard that moment as the start of a new life.¹

Both types have known side effects. The copper IUD often causes heavier periods and more cramping. The hormonal IUD often causes irregular bleeding or amenorrhea, the absence of periods.

Without periods, the cycle cannot serve as a source of diagnostic data. This loss removes information that restorative clinicians use to detect hormonal patterns and hidden disease. Both types carry a small risk of expulsion, in which the device slips out. They also carry a small risk of perforation of the uterus during insertion, and of pelvic infection.

Instead of an IUD, couples can use Fertility Awareness-Based Methods. These methods require no device. They also require no hormones, whether systemic or delivered to the uterus alone. They also avoid any effects after conception. Those effects have raised ongoing debate, both scientific and ethical. The effectiveness of these methods depends on the method, the quality of instruction, and consistent use.

FABMs help couples understand the cycle rather than suppress or override it. They also support body literacy and restorative care.