An intrauterine device (IUD) is one of the most effective forms of long-acting reversible contraception (LARC), with a failure rate of less than one percent in the first year of typical use. Both hormonal and copper IUDs offer efficacy comparable to permanent sterilization. Despite this strong protection, an unintended conception remains a rare occurrence that requires immediate attention and specific medical guidance.
Recognizing the Unexpected Signs
The realization that an IUD has failed often begins with the emergence of typical early pregnancy symptoms. These can include unexplained fatigue, persistent nausea, and heightened tenderness or fullness in the breasts. Individuals may also report new food aversions, increased cravings, or noticeable shifts in mood that differ from their usual pre-menstrual experience.
A change in the menstrual pattern is often the most confusing sign, as both types of IUDs can already alter bleeding. A copper IUD user may notice a complete cessation of their expected period. Users with a hormonal IUD, who may already have light or absent periods, might instead observe a significantly different flow, such as unexpected spotting or a very scant period. Any deviation from the established bleeding pattern should prompt suspicion, especially when combined with other new physical symptoms.
Another important physical sign is a change in the IUD strings, which hang just outside the cervix. Regular self-checks might reveal that the threads feel shorter or longer than normal, or they may be entirely absent. A change in the length of the strings indicates that the device may have moved or partially expelled, reducing its contraceptive effectiveness and increasing the risk of pregnancy.
Identifying Symptoms Requiring Emergency Care
When pregnancy occurs with an IUD in place, the risk of an ectopic pregnancy is significantly elevated. This is a life-threatening condition where the fertilized egg implants outside the uterus, typically in a fallopian tube. It is important to recognize the signs that indicate a medical emergency and require immediate care. These symptoms are distinct from the general discomfort of early pregnancy.
The most concerning warning signs involve severe abdominal or pelvic pain, especially if localized intensely on one side. This unilateral pain can signal that the fallopian tube is stretching or has ruptured. Sudden, sharp pain that does not resolve with rest or mild pain medication should be treated as an emergency.
Referred pain in the tip of the shoulder is another serious sign, resulting from internal bleeding that irritates nerves under the diaphragm. Profound weakness, severe dizziness, or fainting indicate significant blood loss and circulatory distress. If any of these signs appear, seeking immediate medical attention is necessary to prevent serious complications.
Confirming the Diagnosis
Once symptoms raise suspicion, the first step is usually an at-home urine pregnancy test, which is highly accurate when used correctly. A positive home result necessitates a prompt visit to a healthcare provider to confirm the pregnancy and determine its location. Clinical confirmation involves a blood test to measure the level of Human Chorionic Gonadotropin (HCG), the pregnancy hormone.
The most important diagnostic tool is the transvaginal ultrasound. This imaging technique confirms the presence of a pregnancy and identifies its location, crucially ruling out an ectopic implantation. The ultrasound also attempts to locate the IUD itself, determining if it is still positioned within the uterine cavity, partially expelled, or if it has migrated.
If the IUD is not visible inside the uterus on the ultrasound, further investigation may be needed. This determines if it was expelled without being noticed or if it perforated the uterine wall and moved into the abdominal cavity. The combination of HCG levels and ultrasound imaging provides the necessary information for a safe management plan.
Medical Management After Confirmation
For a confirmed intrauterine pregnancy with the IUD still in place, medical consensus advises early removal if the strings are visible and the pregnancy is in the first trimester. Retaining the IUD significantly increases the risk of adverse outcomes. These include a spontaneous miscarriage risk of 40 to 50 percent, a nearly doubled risk of preterm birth, and increasing the risk of a severe uterine infection (septic abortion) by three to five times.
The gentle removal of the IUD reduces the risk of miscarriage to approximately 20 to 25 percent, a substantial improvement over leaving it in place. While the procedure carries a small, immediate risk of triggering a miscarriage, the long-term benefits of a safer pregnancy generally outweigh this risk. If the IUD strings are not visible, the provider may attempt removal using specialized tools under ultrasound guidance. In some cases, the IUD may need to be left in place due to the risk of disturbing the developing pregnancy.
When the IUD cannot be safely removed, the pregnancy must be monitored closely by a specialist due to the continued elevated risks. The IUD does not cause birth defects, but the increased probability of infection and preterm delivery means careful surveillance is required throughout the gestational period. After delivery, the IUD will be located and removed, often found embedded in the placenta or uterine wall.