The Intrauterine Device (IUD) is a highly effective form of long-acting reversible contraception, offering pregnancy prevention for several years with a failure rate of less than one percent. This small, T-shaped device is placed inside the uterus, making it one of the most reliable birth control methods available. A common concern is the possibility of the device moving from its intended position within the uterine cavity. This movement, referred to as dislodgement or expulsion, compromises the IUD’s effectiveness and requires prompt medical attention.
Understanding IUD Expulsion
IUD expulsion is the process where the device partially or completely moves out of the uterine cavity and into the cervix or vagina. This is the most common form of IUD movement, occurring in an estimated two to five percent of users, most frequently within the first few months after insertion. A partial expulsion means the device has slipped down but remains within the cervix or lower uterus, while a complete expulsion means it has entirely left the body. In either case, the IUD is no longer correctly positioned to provide reliable contraception.
Perforation and Migration
It is important to differentiate expulsion from other complications involving device movement, such as uterine perforation or migration. Perforation is a rare event where the IUD pushes through the muscular wall of the uterus, usually happening at the time of insertion. Migration is the movement of the IUD outside the uterine cavity into the pelvic or abdominal space. Expulsion, unlike perforation or migration, is typically signaled by symptoms that alert the user that the IUD is no longer in the correct place.
Factors Increasing the Risk of Dislodgement
The likelihood of IUD expulsion is significantly higher in certain situations. The most significant risk factor is recent childbirth, particularly when the IUD is inserted in the immediate postpartum period. Insertion shortly after delivery carries a higher expulsion rate because the uterus is still returning to its pre-pregnancy size, and these muscular contractions can push the device out.
A history of previous IUD expulsion also increases the risk of a subsequent event. Individuals who experience severe menstrual cramping or heavy menstrual bleeding are more likely to expel the device due to strong uterine contractions. Anatomical factors can contribute to dislodgement, including a smaller-than-average uterus or the presence of uterine fibroids, which can distort the uterine cavity shape.
Adolescents and younger individuals (under age 20) have a slightly increased risk compared to older adults. The highest overall risk period for expulsion is during the first three months following the initial insertion. After this initial adjustment period, the chance of the IUD moving significantly decreases.
Recognizing the Signs of Expulsion
The most direct way to monitor the IUD’s position is by performing a monthly string check, ideally after the menstrual period has ended. The strings are thin threads attached to the IUD that hang into the vagina. A change in the length of these retrieval strings is often the first indication of movement. If the strings feel noticeably longer or shorter, or if they cannot be felt at all, the IUD may be dislodged.
Physical symptoms can also signal that the device is no longer correctly positioned. Users may experience new or significantly worsened cramping, manifesting as sharp pelvic pain not relieved by over-the-counter medication. Abnormal bleeding patterns, such as heavy bleeding, prolonged spotting, or the sudden return of heavy periods, can also be a symptom of partial expulsion.
In the case of partial expulsion, the hard plastic tip of the IUD itself may become palpable. If a user feels the firm plastic T-shape protruding from the cervix, or if a partner reports feeling the plastic during intercourse, expulsion is confirmed and requires immediate medical attention.
Immediate Steps and Medical Follow-Up
If expulsion is suspected, assume that contraceptive protection has been lost. Immediately begin using a non-IUD method of birth control, such as condoms, to prevent unintended pregnancy. Users must avoid attempting to push the IUD back into place or removing it themselves, as this can cause injury or severe discomfort.
Contact a healthcare provider immediately to schedule an urgent evaluation. The provider will perform a pelvic examination to visualize the strings or the device. If the strings are not visible, an ultrasound will be ordered to determine the IUD’s precise location within the body.
If the IUD is not found in the uterus, an X-ray of the pelvis and abdomen may be necessary to rule out perforation and locate the device elsewhere. Once confirmed, the IUD will be removed, and the user can discuss options for replacement or an alternative contraceptive method.