How Likely Is It To Get Pregnant With An Iud?

Getting pregnant with an IUD in place is rare, but it can happen. The failure rate is less than 1% for most hormonal IUDs and the copper IUD. That means fewer than 1 out of every 100 women using an IUD will become pregnant in a year. It is one of the most effective forms of birth control available, but no method is perfect.

How Effective Are IUDs at Preventing Pregnancy?

IUDs are among the most reliable contraceptive methods we have. Both the copper IUD and hormonal IUDs have failure rates below 1% with typical use. This is much better than birth control pills, which have a typical failure rate around 7% because people sometimes forget to take them.

One reason IUDs work so well is that they require no daily action. Once placed, they work continuously. The copper IUD works for up to 10 years. Hormonal IUDs work for 3 to 8 years depending on the brand. Over that entire time, the risk of pregnancy stays very low.

How Does an IUD Prevent Pregnancy?

The copper IUD and hormonal IUDs work differently, but both target sperm and fertilization.

The copper IUD releases copper ions into the uterus. Copper is toxic to sperm. It changes the way sperm move and prevents them from reaching the egg. It also changes the lining of the uterus, making it less hospitable for implantation if fertilization somehow occurs.

Hormonal IUDs release a progestin called levonorgestrel. This hormone thickens the cervical mucus, which blocks sperm from entering the uterus. It also thins the uterine lining and may prevent ovulation in some women, though not consistently.

Both types primarily prevent fertilization rather than implantation. This is an important distinction because many people believe IUDs work mainly by preventing a fertilized egg from implanting. The evidence points to sperm blockage and damage as the main mechanism.

What Happens If You Get Pregnant With an IUD?

If pregnancy occurs with an IUD in place, there are two major concerns. The first is ectopic pregnancy. The second is infection.

An ectopic pregnancy happens when the fertilized egg implants outside the uterus, usually in a fallopian tube. IUDs do not increase the overall risk of ectopic pregnancy compared to no contraception. However, if a pregnancy does occur with an IUD in place, it is more likely to be ectopic than a pregnancy without an IUD. This is because the IUD prevents most uterine pregnancies but does not always prevent implantation in the tube.

If you have a positive pregnancy test with an IUD, you need medical evaluation quickly. Your doctor will need to rule out an ectopic pregnancy with an ultrasound and blood tests. Ectopic pregnancy is a medical emergency and can be life-threatening if untreated.

Infection is another risk. The presence of an IUD during pregnancy increases the risk of pelvic infection, which can be dangerous for both you and the pregnancy. This is one reason doctors usually recommend removing the IUD if pregnancy is confirmed and the pregnancy is in the uterus.

Can the IUD Be Removed During Pregnancy?

If the pregnancy is in the uterus and the IUD strings are visible, a doctor can often remove the IUD. This is generally recommended. Removing the IUD reduces the risk of miscarriage, infection, and preterm birth.

Research shows that removing the IUD early in pregnancy lowers the miscarriage rate compared to leaving it in place. The procedure is quick and similar to getting the IUD inserted. It carries a small risk of causing the miscarriage itself, but the overall evidence favors removal.

If the IUD strings are not visible, removal is more complicated. The IUD may have moved or become embedded. In this case, your doctor will discuss options based on ultrasound findings. Sometimes the IUD is left in place for the duration of the pregnancy, but this increases risks.

What Are the Signs of Pregnancy With an IUD?

Pregnancy symptoms with an IUD are the same as pregnancy symptoms without one. Missed periods, breast tenderness, nausea, and fatigue are common early signs.

However, some women with hormonal IUDs have very light or absent periods as a normal effect of the device. This can make it harder to notice a missed period. If you experience unusual bleeding, pelvic pain, or a positive home pregnancy test, contact your doctor.

Severe pelvic pain, especially on one side, along with dizziness or shoulder pain, can be signs of ectopic pregnancy. These symptoms require immediate medical attention.

How Likely Is It To Get Pregnant With an IUD After Insertion?

The first few weeks after insertion are the highest-risk period for IUD failure. This is because the IUD may not yet be fully positioned, or it may be expelled without you noticing.

Expulsion is when the IUD partially or completely comes out of the uterus. It happens in about 2 to 10% of users, most often in the first year. If the IUD is expelled and you do not realize it, you are no longer protected from pregnancy.

Doctors often recommend a follow-up visit about 4 to 6 weeks after insertion to confirm the IUD is still in place. You can also check the strings yourself periodically. If you cannot feel the strings, or if you feel the plastic tip of the IUD, use backup contraception and see your doctor.

Does Pregnancy With an IUD Affect the Baby?

If the IUD is removed early in pregnancy, the risk of birth defects does not appear to be increased. The copper and the hormones in IUDs have not been linked to fetal abnormalities when the pregnancy continues.

If the IUD is left in place, the risks are higher. These include miscarriage, preterm birth, and infection of the amniotic sac. The chance of a live birth is lower when the IUD stays in place throughout the pregnancy.

Every situation is different. Your doctor will guide you based on how far along you are, where the IUD is located, and your overall health.

What Are the Alternatives If You Want Highly Effective Birth Control?

If you are considering an IUD, the alternatives with similar effectiveness are the contraceptive implant and permanent sterilization.

The contraceptive implant is a small rod placed under the skin of the upper arm. It releases progestin and works for up to 3 years. Its failure rate is below 1%, similar to an IUD.

Sterilization procedures, such as tubal ligation for women or vasectomy for men, have failure rates below 1% as well. These are permanent and not easily reversed.

Birth control pills, patches, rings, and shots are less effective with typical use because they depend on consistent action. They are good options for many people, but they do not match the reliability of an IUD or implant.