Reasons for an Ectopic Pregnancy
Any woman or person capable of conceiving of child-bearing age, who is sexually active or undergoing assisted reproductive technology (ART) treatment, is at risk of an ectopic pregnancy. Detailed general information can be found here on our website. Please remember that online medical information is no substitute for expert medical care from your own healthcare team.
Causes of Ectopic Pregnancy
Often the reason for the ectopic pregnancy will never be determined. However, ectopic pregnancies are more likely if you have had:
- Previous ectopic pregnancy: There is an increased risk of a subsequent ectopic pregnancy after someone has experienced an ectopic pregnancy.
- Fertility treatment: There is a chance of ectopic pregnancy resulting from embryo transfer during IVF treatment as embryos can travel into the Fallopian tube, for example, during the implantation stage. The more embryos that are transferred, the higher the risk.
- Older age: There is an increased risk of ectopic pregnancy for older women.
- Pelvic Inflammatory Disease: This is a past infection of the Fallopian tubes caused, for example, by a sexually transmitted infection like chlamydia trachomatis.
- Tubal surgery: An operation on the Fallopian tubes, such as sterilisation.
- Endometriosis: This is a condition where cells like the ones lining the womb grow elsewhere in the body but still react to the menstrual cycle each month and bleed despite there being no way for the blood to leave the body. It is not known why endometriosis increases the risk of ectopic pregnancy.
- Abdominal surgery: Any previous operation on the tummy, such as caesarean section or appendicectomy.
- Intrauterine Device (IUD): Intrauterine devices (coil) prevent pregnancy in the womb but is less effective in preventing pregnancy in a Fallopian tube.
- Emergency contraception: It is possible to become pregnant in the same cycle after trying to prevent pregnancy with emergency oral contraception. While not proven, there is the biological plausibility that emergency contraception could increase the risk of ectopic pregnancy. If the emergency contraception is effective and manages to prevent ovulation, it will decrease the risk, but if it fails to do so, there may be an increased risk of ectopic pregnancy.
- Cigarette smoking: Research by the University of Edinburgh shows that smokers have an increased level of the protein PROKR1 in their Fallopian tubes. The protein is instrumental in helping pregnancies implant in the womb, but when present in the Fallopian tubes can hinder the progress of a fertilised egg, increasing the chances of a pregnancy being ectopic.
The following commonly asked reasons are NOT causes of ectopic pregnancy:
- Ectopic pregnancy is not hereditary: i.e., it is not a condition that passes from parent to offspring. You are no more at risk of an ectopic pregnancy than anyone else, even if your immediate family members suffered.
- Miscarriage is not related to ectopic pregnancy: Unfortunately, miscarriage is a very common event that occurs in one in five first trimester (first 12 weeks) pregnancies but there is no link between the two conditions.
- Abortion is not linked to ectopic pregnancy: The decision to terminate pregnancy is a significant decision based on circumstances at the time for an individual. When considering the circumstances around the termination, most would likely arrive at the same decision, time and time again.
- There are many inaccurate articles online, often used as propaganda by anti-abortion groups which make tenuous links between termination and ectopic pregnancy. There is nothing at all, however, to be gained by alarming or blaming ourselves about a termination and whether it might or might not have contributed to a subsequent loss. If you are struggling with this issue do be gentle with yourself and do not believe everything you read on the internet or social media, in the news, or in magazines. Always check the source of the figures that are quoted.
- Importantly, please do not blame yourself for something that cannot be changed and is unlikely to have contributed anyway.
- Exercise and sport in general: Exercise (including intense activity) makes no contribution to ectopic pregnancy.
- Flying: There is no evidence to link ectopic pregnancy to flying in a plane. If you have been diagnosed with an ectopic pregnancy or might have an ectopic pregnancy, you should not take flights on planes.
- Benzodiazepine: A study shows an association with use of Benzodiazepine (more commonly known as Valium and Xanax) and ectopic pregnancy. The EPT strongly suggests that this study be interpreted with caution. The study is not designed to show precise cause and there may be many reasons why women who have been prescribed with the drug might have higher incidence of ectopic pregnancy. In other words, the increased incidence of ectopic pregnancy may not be directly linked to use of the drug. As a causal link has not been shown, more research is needed and, accordingly, you should not change medication prescribed by your doctor.