We’ve heard it all before. The conversation surrounding “choice” and how some couples, even after having used contraception, can still get pregnant through failures of their preferred method. Although it’s a rare occurrence, it can still happen. Therefore, it is beneficial for us to understand how and why this might happen, how we can try to lower the chance of failure, and what to do if you find yourself pregnant despite having used contraception. On this blog, we will focus on one of the more popular long-term contraceptive methods—the IUD (Intrauterine Device).
How does pregnancy work?
Pregnancy is the process in which the implantation of a zygote (an egg/ovum that has been fertilized by a sperm) onto the uterus lining is successful. Implantation typically begins around six days after fertilization and takes several days to complete. If no fertilization or implantation happens, the uterine lining sheds during menstruation.
This is where contraception comes in. So, technically, contraception works by preventing the said processes that either allow a successful fertilization or a successful implantation.
Different contraceptives work differently to prevent pregnancy. You can find out more about the different types of contraception here.
How does an IUD work to prevent pregnancy?
An IUD is a small, T-shaped device made of either copper or hormone-releasing plastic that is placed in the uterus through the cervix to prevent fertilization. It has two strings that extend into the vagina, allowing a healthcare provider—such as a doctor, nurse practitioner, or physician assistant—to remove it when it expires, or when the user wants to become pregnant, or in rare cases when complications arise.
As we all know, there are two types of IUD. The hormonal IUD releases the hormone progestin into the uterus and may last from 3 to 8 years of use, depending on the brand, while the copper IUD releases copper into the uterus and may last up to 10 years.
The hormonal IUD prevents pregnancy in two ways: First, it thickens the cervical mucus, making it difficult for sperm to reach or fertilize an egg. Second, it also thins the uterine lining and partially prevents ovulation, which is the release of an egg from the ovary.
The copper IUD, on the other hand, does not release any hormone, but it releases copper. Copper impedes the process of fertilization by affecting the sperm’s function and movement, given that copper is toxic to sperm.
Instances in which you can get pregnant while having IUD
According to the American College of Obstetricians and Gynecologists, the IUD and the implant are the most reliable reversible birth control methods. In the first year of use, fewer than 1 out of 100 users becomes pregnant. Over the long term, these long-acting reversible contraceptives (LARCs) are about 20 times more effective than the pill, patch, or vaginal ring. Nevertheless, there are still chances of failure.
According to the Centers for Disease Control and Prevention (CDC), copper IUDs have a failure rate of 0.8%, while hormonal IUDs range from 0.1% to 0.1–0.4%.
There are many ways in which IUD contraception might fail.
To start, it has something to do with the waiting period of certain IUDs, more specifically, hormonal IUDs. As opposed to the copper IUD, which works right away after insertion, the hormonal IUD works a little differently. The typical rule is, if it is placed more than 7 days after the period, you need to use a backup contraceptive method for the first 7 days after insertion. If you have unprotected sex immediately after insertion, then pregnancy has a higher chance to take place. The timing of initiation of hormonal IUD varies slightly in different gynecological settings, as summarized in the table below.
Timing of Initiation of Copper IUD vs Hormonal IUD
Another instance is the risk of expulsion. The expulsion of an IUD technically means that the IUD is not in place; either it is moved too far out of the uterus or too far up into the uterus or expelled from the uterus completely, affecting its efficacy in preventing pregnancy. According to a study in the US, a history of heavy menstrual bleeding is the strongest predictor of IUD expulsion. Other high-risk groups include individuals who are overweight or obese, under age 25, or have had four or more births.
Lastly, the expiration date. As mentioned before, according to different brands, IUDs have different expiration dates. For example, Skyla is three years, Kyleena is five years, Liletta is six years, Mirena is up to eight years, Levosert is six years, and Jaydess is three years. The copper ParaGard lasts up to 10 years. Therefore, you need to be careful to look at the expiration date and the brand and switch to a new one before it expires. Once it expires, the efficacy in preventing pregnancy will not be the same, which may lead to one.
The risks of pregnancy with IUD
Leaving an IUD in during pregnancy is linked to higher risks of miscarriage, preterm birth, and infections like chorioamnionitis. Removing the IUD can lower these risks, but complications still occur more frequently than in pregnancies without an IUD.
IUDs don’t directly cause ectopic pregnancies, but because they are highly effective at preventing normal pregnancies inside the uterus, any pregnancy that does occur while using an IUD is more likely to be ectopic. This is particularly relevant in the early weeks after insertion, when mild irritation or infection of the fallopian tubes can occur, and especially if the IUD is left in place beyond its recommended time. Copper IUDs may slightly increase the risk of inflammation in the fallopian tubes.
An ectopic pregnancy happens when a fertilized egg implants outside the uterus, most often in a fallopian tube, and can be linked to factors like prior pelvic infections, surgeries, endometriosis, or tubal damage. Still, the overall risk remains low: only about 0.02% of hormonal IUD users and 0.05% of copper IUD users experience an ectopic pregnancy each year, according to one study in the US.
What to do if you suspect pregnancy while having an IUD?
The first and most important step you need to take is to confirm the pregnancy once you observe the signs.
If you think you might be pregnant while using an IUD, start by taking a home pregnancy test. If the result is negative but you still have concerns, contact your healthcare provider for further evaluation or testing. If the test is positive, you can chat with Ally, our safe abortion chatbot, to discuss your options. Ally is here for you 24/7 to guide you through your choices, free of judgement. However, if you experience pelvic pain on one side along with vaginal bleeding and can’t get in to see a healthcare provider promptly, it’s important to go to the emergency room, as this could be a sign of an ectopic pregnancy.
On the other hand, once you find out that it’s an intrauterine pregnancy, you can either choose to carry it to term, in which case you will need to ask your healthcare provider to locate the IUD and remove it as soon as possible, or you may exercise your rights to receive an abortion. You can find information on how to self-manage your abortion with pills at home on our website.
After abortion, you may find that there are contraception methods that you may choose.
Just because it failed once does not mean that you should avoid using long-acting contraception or even an IUD. What you need to do is to take care of it and know when to get checked regularly and to seek medical help if something doesn’t feel right. For IUDs, you can get them placed right after your abortion; however, if inserted immediately after an abortion, you should wait 7 days before having sex without another form of contraception, such as a condom.
In conclusion, while IUDs are among the most effective forms of contraception, pregnancies can still occur, even though they are rare. The risk of pregnancy includes the timing of initiation, the possibility of expulsion or misplacement, or the expiration of the IUD. If pregnancy occurs with an IUD, it is important to seek medical attention right away, as there is an increased risk of complications, including miscarriage, preterm birth, and infections. Ectopic pregnancies, though more likely when using an IUD, remain uncommon overall. The first step is to confirm the pregnancy with a home test and follow up with your healthcare provider for an ultrasound and exam. If the pregnancy is intrauterine, options include removing the IUD or considering an abortion. Regular checkups and awareness of the IUD’s expiration date are essential for ongoing effectiveness and safety.