Nexplanon is a long-acting reversible contraception (LARC) designed to prevent pregnancy. This small, flexible implant is approximately the size of a matchstick and is discreetly inserted by a healthcare professional just beneath the skin of the upper arm. Nexplanon continuously releases a progestin hormone to provide consistent birth control.
Effectiveness of Nexplanon
Nexplanon is considered one of the most effective birth control methods available. It is over 99% effective, meaning fewer than 1 in 100 users become pregnant annually. This high success rate is primarily due to its mechanism of action and the elimination of user error.
The implant releases a steady, low dose of the hormone etonogestrel, which is a type of progestin. This hormone works in multiple ways to prevent pregnancy: it primarily stops ovulation. Additionally, it thickens the mucus in the cervix, creating a barrier that makes it difficult for sperm to reach an egg, and thins the lining of the uterus, which makes implantation of a fertilized egg less likely. Because the implant is placed once and works continuously, it removes the need for daily pills or other regular actions.
Factors That Reduce Effectiveness
While Nexplanon is highly effective, certain factors can potentially reduce its ability to prevent pregnancy. One such factor is improper insertion. If the implant is not placed correctly under the skin by a trained healthcare provider, it may not effectively release the hormone. In rare instances, an improperly inserted implant may be difficult to locate for removal, or it might even migrate.
Drug interactions can also impact Nexplanon’s effectiveness. Certain medications can interfere with the hormone levels released by the implant, reducing its effectiveness. These include specific anticonvulsants like carbamazepine, felbamate, oxcarbazepine, phenytoin, and topiramate. Some antibiotics, particularly rifampin, and certain HIV medications, as well as the herbal supplement St. John’s wort, can also reduce Nexplanon’s efficacy. It is important to inform a healthcare provider about all medications and supplements being taken to assess potential interactions.
Research suggests that Nexplanon may be less effective in individuals with higher body mass index (BMI). However, for most users, it remains a reliable contraceptive choice regardless of weight. Additionally, if the implant is left in place beyond its recommended three-year lifespan, its hormone-releasing capacity diminishes, increasing the risk of pregnancy. Physical damage to the implant, though highly unlikely, could compromise its function.
Recognizing Potential Pregnancy
Even with the high effectiveness of Nexplanon, it is important to be aware of potential signs of pregnancy. Common indicators can include nausea, breast tenderness, and fatigue. Other symptoms that might suggest a pregnancy include frequent urination, changes in appetite, and sensitivity to smells.
Nexplanon can alter menstrual bleeding patterns, ranging from irregular spotting to no periods at all. Therefore, a missed period, which is a common early sign of pregnancy for those not on hormonal birth control, may not be a reliable indicator when using Nexplanon. If any concerning symptoms arise, taking a home pregnancy test can provide an initial assessment.
Next Steps If Pregnancy is Suspected
If pregnancy is suspected while using Nexplanon, seeking prompt medical confirmation from a healthcare provider is important. A doctor or gynecologist can perform tests, such as blood tests or an ultrasound, to confirm a pregnancy. Early confirmation allows for medical guidance.
If pregnancy is confirmed, the Nexplanon implant must be removed. Leaving the implant in place during pregnancy carries a slightly higher chance of an ectopic pregnancy, where the fertilized egg implants outside the uterus. Ectopic pregnancies are serious and may require immediate medical intervention. While generally no evidence suggests harm to the fetus from the hormones if pregnancy occurs with the implant, removal is still recommended. Following removal, the healthcare provider will discuss pregnancy options and next steps.