We’ve already blogged about Nexplanon’s side effects [see Nexplanon: Weight Gain, Menstrual Bleeding, & Depression] but, based on our visitor queries, it is clear that some of you are less interested in the contraceptive implant’s side effects and are more interested in the following:
Can Nexplanon fail? What will cause Nexplanon to fail?
Nexplanon failure occurs when the implant is improperly inserted which may then lead to unintended pregnancy. Here’s a video which demonstrates how a contraceptive implant is inserted correctly. [We know the video is for Implanon but the insertion technique is the same for Nexplanon.]
Now, even if it is placed correctly, there is still the possibility of a woman getting pregnant but this is very very low (less than 1 pregnancy per 100 women who use NEXPLANON for 1 year). See how it compares with other contraceptive methods in the image below (please click to expand).
It is worth noting that the implant may also be less effective for overweight women. Here’s what the manufacturer (Merck) says in its prescription information:
The effectiveness of the etonogestrel implant in women who weighed more than 130% of their ideal body weight has not been defined because such women were not studied in clinical trials. Serum concentrations of etonogestrel are inversely related to body weight and decrease with time after implant insertion. It is therefore possible that NEXPLANON may be less effective in overweight women, especially in the presence of other factors that decrease serum etonogestrel concentrations such as concomitant use of hepatic enzyme inducers.
By the way, should a woman get pregnant while using Nexplanon, the probability that her pregnancy is ectopic is higher than those who not using birth control.
According to the National Library of Medicine of the National Institutes of Health, “unusual vaginal bleeding or lower stomach (abdominal) pain may be a sign of ectopic pregnancy. Ectopic pregnancy is a medical emergency that often requires surgery”. If unattended, ectopic pregnancies can “cause serious internal bleeding, infertility, and even death”.