Intrauterine Contraception (IUC) is a highly effective, long-acting method of preventing pregnancy. This form of birth control is placed directly inside the uterus, offering continuous protection for several years. IUC is a low-maintenance option that removes the possibility of user error common with daily pills or other barrier methods.
Defining Intrauterine Contraception
Intrauterine Contraception refers to a small, flexible device, typically shaped like the letter “T,” that a healthcare provider inserts into the uterus. These devices are made of plastic and conform to the shape of the uterine cavity. A thin string is attached to the bottom of the device, remaining in the upper part of the vagina for placement check and eventual removal.
The terms IUC and Intrauterine Device (IUD) are often used interchangeably. IUD is the older, more widely recognized name, while IUC emphasizes the device’s function as a contraceptive method. IUC is classified as a form of Long-Acting Reversible Contraception (LARC).
It provides continuous pregnancy prevention for an extended duration, and fertility returns quickly once the device is removed. These devices are highly effective, boasting an efficacy rate of over 99% in preventing pregnancy.
Hormonal Versus Copper IUC Devices
IUC devices are divided into two categories based on their composition and mechanism of action. These two types offer different options based on health needs and preferences regarding hormones.
Hormonal IUC
The hormonal IUC, sometimes called an Intrauterine System (IUS), releases a synthetic version of progesterone called levonorgestrel directly into the uterus. Different brands vary in the amount of hormone they contain and their approved duration of use, which ranges from three to eight years. The hormone’s action is localized, meaning very little enters the bloodstream compared to hormonal pills.
Copper IUC
The copper IUC contains no hormones and is suitable for people who prefer non-hormonal methods. This device is made of a plastic T-frame with a fine copper wire wrapped around its stem and arms. The copper IUC has the longest approved lifespan, with some devices protecting against pregnancy for up to ten or twelve years. This option works solely through the action of the metal within the uterine environment.
How IUC Prevents Conception
Each IUC type prevents conception through specific biological processes.
Hormonal Mechanism
The hormonal IUC primarily acts by altering the environment of the cervix and uterus. It releases progestin, which causes the cervical mucus to become thicker and stickier, creating a physical barrier that blocks sperm from entering the uterus. Progestin also thins the endometrium (the lining of the uterus).
This thinning makes the uterine environment less hospitable for a fertilized egg. The localized dose of the hormone can also impair sperm function and movement within the uterus.
Copper Mechanism
The copper IUC utilizes the metal to create an environment toxic to sperm and eggs. Copper ions trigger a localized sterile inflammatory response within the uterus. This reaction acts as a spermicide, impairing the viability and motility of sperm.
The copper ions effectively prevent sperm from reaching the egg in the fallopian tubes, which is the primary contraceptive mechanism. The copper IUC is effective immediately upon insertion and can be used as a highly effective form of emergency contraception.
The Insertion and Removal Process
The process of placing an IUC device is a minor medical procedure that must be performed by a trained healthcare professional. Before insertion, the provider confirms the patient is not pregnant and may screen for infections. The procedure usually takes only a few minutes in a clinic or office setting.
Insertion
During insertion, a speculum is used to visualize the cervix. A specialized narrow tube guides the folded IUC through the cervical opening into the uterus. Once inside the uterine cavity, the arms of the T-shaped device open up, and the insertion tube is withdrawn. The attached retrieval strings are then trimmed so they extend a short distance into the vagina.
Removal
Removal is faster, involving the healthcare provider gently pulling on the retrieval strings. The arms of the T-shaped device fold up as the IUC is pulled out of the uterus and through the cervix. The removal process is quick, often taking less than a minute. A significant advantage of IUC is the immediate return to prior levels of fertility upon removal. Individuals can have the device removed at any time they wish to attempt pregnancy.