Intrauterine devices and ectopic pregnancy: questions answered

An intrauterine device (IUD) is a small, plastic, T-shaped device that is put into the uterus (womb) by a doctor or nurse to stop pregnancy from occurring. It is a form of reversible contraception, like the contraceptive pill, implant, and injection. IUDs, also known as coils, offer long-lasting birth control and can be left in for 3-10 years, depending on the type, but they can be removed at any time. IUDs can be hormonal or non-hormonal (copper). 

IUDs prevent pregnancy by releasing a synthetic progesterone called levonorgestrel hormone (hormonal IUD, also known as an intrauterine system or IUS, e.g. Mirena) or copper ions (copper or non-hormonal IUD) into the uterus, making it inhospitable to sperm and pregnancies. IUDs are more than 99% effective at preventing pregnancy.  

Unfortunately, IUDs do come with a risk of pregnancy, including ectopic pregnancy, although they are rare. In an ideal world IUDs – and all forms of contraception – would be 100% effective at preventing pregnancy, but unfortunately, they are not. This means that there is a small chance of becoming pregnant with an IUD in place.  

If an IUD is kept past its recommended removal deadline, it is not guaranteed to prevent pregnancy, and other forms of contraception should be used until it can be removed. IUD pregnancies can also happen due to IUD ‘expulsion’, where the IUD falls out, or if it moves out of place from the top of the uterus where it should sit. Finally, there is a high risk of pregnancy with a hormonal IUD that has not started to work yet; backup contraception should be used for the first seven days after getting the hormonal IUD put in. Copper IUDs work immediately after insertion.

Although the chance of getting pregnant with an IUD in place is low, if you do get pregnant with an IUD, it is more likely to be an ectopic pregnancy. This is because IUDs are so effective at preventing pregnancies in the uterus, if a pregnancy does occur, it is more likely to occur outside of the uterus. IUD-related ectopic pregnancies can be very traumatic and confusing. Lily experienced an ectopic pregnancy while using an IUD, and shared her experience with The Ectopic Pregnancy Trust: 

“I had very confused feelings since the pregnancy was not planned, yet I still felt an immense sense of loss and grief”. 

We understand the complicated feelings that come with IUD-related ectopic pregnancy and we are here to support anyone going through this. If you need support yourself, or know someone that you think needs our help, please do read more about how The EPT can help. 

Concerning ectopic pregnancy with an IUD, the IUD does not directly cause ectopic pregnancy; rather, it prevents typical intrauterine pregnancies (normally-sited), but it does not prevent ectopic pregnancies. Copper IUDs can also increase the risk of ectopic pregnancy by causing inflammation in the Fallopian tubes. Both types of IUD, particularly during insertion and for the first 20 days, may lead to irritation or infection of the Fallopian tubes. Keeping an IUD past its removal date also increases the risk of infection.  

An ectopic pregnancy occurs when a fertilised egg implants and grows outside the uterus (womb). Most commonly, an ectopic pregnancy occurs in one of the Fallopian tubes, which carry eggs from the ovaries to the uterus; also known as a tubal pregnancy. Ectopic pregnancies can also occur in the cervix, abdomen, or ovary. Tubal pregnancies occur when the fertilised egg gets stuck in a Fallopian tube on its way to the uterus. The egg may get stuck due to the Fallopian tube being misshapen, inflamed, or otherwise damaged (for example, due to scarring), and hormonal imbalances may also play a part. Risk factors include previous ectopic pregnancy, pelvic inflammatory disease (PID), certain sexually transmitted infections (STIs), previous pelvic, abdominal, or Fallopian tube surgery, and endometriosis.

A review of IUD safety and efficacy stated that ectopic pregnancies affect 2 in 10,000 women with hormonal IUDs, and 5 in 10,000 copper IUD users, each year. That corresponds to 0.02% and 0.05%, respectively. Comparatively, the overall incidence of ectopic pregnancy in the UK is 1.25% (1 in 80). So although the pregnancy itself is more likely to be ectopic when the woman has an IUD, the chance of getting pregnant is much lower, meaning the overall risk of ectopic pregnancy is drastically reduced.

Though an IUD does increase the chance of a pregnancy being ectopic while it is in place, there is no increased risk of ectopic pregnancy after IUD removal. In fact, there is no higher risk of any pregnancy complications after IUD removal. In most cases, IUD removal or previous IUD use does not affect fertility. However, in the very rare cases that there is scarring in the uterus from the IUD, particularly following an infection, this may reduce the chances of becoming pregnant and having a viable pregnancy.  

IUDs are safe and mostly very easy to remove. Removal will be carried out by a medical professional. Although IUDs are effective and can stay in place for between 3 and 10 years, they can be removed at any time. Generally, it will be removed by pulling the threads with ring forceps. However, if the IUD threads snap or cannot be reached, it will need to be removed by ultrasound-guided removal or a removal procedure known as a hysteroscopy.  

Signs of early ectopic pregnancy may be very similar or identical to the usual signs of pregnancy: 

• A missed period 
• Nausea 
• Vomiting 
• Tender or swollen breasts 
• Increased urination 
• Fatigue 

Additional symptoms associated with ectopic pregnancies may also be experienced. These include:  

• Pelvic pain or abdominal pain or discomfort 
• Vaginal bleeding or an abnormal period 

Ectopic pregnancies can lead to rupturing of the Fallopian tube, which can have life-threatening consequences. Symptoms of this should be treated as a medical emergency, and include:  

• Heavy bleeding 
• Pain at the tip of the shoulder 
• Pain or pressure in the rectum 
• Sharp, sudden pains or cramping in the stomach 
• Extreme lightheadedness or dizziness 
• Fainting 
• Shock  
• Looking extremely pale