An Intrauterine Device (IUD) is a small, T-shaped contraceptive device designed to prevent pregnancy. It is a form of long-acting reversible contraception (LARC), offering effective birth control for several years once in place. Both hormonal and non-hormonal (copper) IUDs exist, each working through slightly different mechanisms to prevent fertilization. These devices are highly effective, with success rates over 99%.
Inside the Uterus
The uterus, often referred to as the womb, is a pear-shaped, hollow, muscular organ situated in the female pelvis. This organ is divided into three main sections: the fundus (the uppermost rounded part), the body (the main central area), and the cervix (the lower, narrow opening that protrudes into the vagina).
The IUD is designed to sit within the uterine cavity. Once inserted, its flexible arms expand laterally, resting against the sides of the upper uterus, or fundus, securing the device. A thin string or two are attached to the bottom of the IUD, which extend down through the cervical canal and typically rest within the upper part of the vagina. This positioning allows the IUD to function effectively by creating an environment in the uterus that discourages pregnancy.
How the IUD is Placed
IUD insertion is a procedure performed by a healthcare provider in a clinic setting, typically taking under 15 minutes. The process begins with a pelvic exam to assess the uterus’s size, shape, and position. A speculum is then inserted into the vagina to hold the vaginal walls open, providing a clear view of the cervix. The cervix and surrounding area are cleaned with an antiseptic solution to minimize the risk of infection.
A special instrument called a tenaculum may be used to gently hold and stabilize the cervix, and a uterine sound is inserted to measure the depth of the uterine cavity, ensuring it is adequate for IUD placement. The IUD is folded into a narrow applicator tube for insertion. This tube is then guided through the cervical opening and into the uterus. Once the IUD is inside the uterine cavity, the applicator tube is withdrawn, allowing the IUD’s arms to unfold into its T-shape. Finally, the strings attached to the IUD are trimmed, leaving a short length extending into the vagina.
Confirming and Monitoring Placement
Healthcare providers confirm the IUD’s placement immediately after insertion. In some cases, a post-insertion ultrasound may be performed to verify the IUD is correctly positioned within the uterine cavity. Ultrasound is a reliable tool for assessing IUD location, especially if there are concerns about its position.
Individuals with an IUD are advised to regularly check for the presence of the IUD strings. This self-check involves inserting a clean finger into the vagina until the cervix is reached and feeling for the thin threads, which feel like fine fishing line. This helps confirm the IUD remains in place. This check is recommended monthly, particularly after a menstrual period, as the IUD is most likely to shift or expel during this time.
If the strings feel longer or shorter than usual, or if the hard plastic part of the IUD can be felt against the cervix, this may indicate the IUD has moved and a healthcare provider should be contacted. While it’s common for strings to coil or be trimmed short, making them difficult to feel, any concerns about IUD position should be addressed by a healthcare provider. If strings cannot be found, an ultrasound can be used to locate the IUD. Until proper placement is confirmed, a backup method of birth control should be used.