Endometriosis is a fairly common condition in women of childbearing age. It occurs when endometrial tissue builds up outside of the uterus. That means the tissue can’t be expelled through the vagina during a period. Endometriosis may affect fertility in some women.

Once pregnant, symptoms of endometriosis may be temporarily alleviated. They tend to return once the pregnancy is complete.

It was previously thought that once a woman with endometriosis became pregnant, the condition wouldn’t affect her pregnancy. However, some recent studies have shown a strong link between endometriosis and miscarriage, though the reason for this link isn’t yet understood. A miscarriage is classified as a pregnancy loss that occurs before 20 weeks of gestation.

What does the research say?

Two large studies recently looked at the relationship between endometriosis and miscarriage. Both studies found endometriosis to be a risk factor for miscarriage. One found a significantly increased risk of previous miscarriage for women with endometriosis. The other cites that the increased risk of miscarriage for women with endometriosis is almost 80 percent. These studies were carried out in 2016 and 2017.

Neither study notes any similarities in the miscarriages, but it’s widely agreed that more research is needed in this area.

Other risk factors

There are some other things that could increase the risk of miscarriage. Being 35 years of age or older is one risk that affects both males and females.

For females only, additional risks include:

  • three or more previous miscarriages
  • obesity
  • polycystic ovary syndrome
  • particular viral or bacterial infections during pregnancy
  • blood-clotting disorders
  • abnormalities in the structure of the uterus
  • exposure to certain medicines or chemicals during pregnancy
  • smoking or using alcohol or cocaine during pregnancy
  • excessive intake of caffeine during pregnancy

Many women wonder if they’ve done something wrong following a miscarriage. Most miscarriages occur because the fertilized egg in the uterus isn’t developing normally, not because of anything they did. Miscarriages aren’t caused by exercise, stress, or sex.

Seeking medical help

Doctors don’t understand the reason for the link between endometriosis and miscarriage, so there’s nothing your doctor can do to reduce your risk. However, they will want to monitor your pregnancy closely.

You may be able to help reduce your risk of miscarriage by avoiding all of the other risk factors for miscarriage and making healthy lifestyle choices. Learn more about maintaining a healthy pregnancy.

Signs of miscarriage

If you experience any of the following symptoms during early pregnancy, it could mean that you are going to have or are having a miscarriage. You should seek medical advice immediately.

  • vaginal bleeding
  • pain and cramping in your lower abdomen
  • fluid releasing from your vagina
  • tissue releasing from your vagina
  • a cessation of pregnancy symptoms

Some light bleeding in pregnancy before 12 weeks can be normal — it isn’t necessarily because of a miscarriage. It’s still best to see your doctor as a precaution. They can assess your symptoms and, if needed, give you an ultrasound to determine whether the fetus is still living and developing as expected.

If your doctor does determine that you’re having a miscarriage, there isn’t usually anything they can do to prevent it. Knowing what is happening can help some women to process it psychologically.

Your doctor will also want to monitor you. Occasionally, tissue from the pregnancy may be retained in the uterus following miscarriage. That can lead to complications. Your doctor will want to be sure this isn’t happening to you. If it is, you may need some medication, or in rare cases, a minor operation.


You may have trouble conceiving if you have endometriosis. You may also be at increased risk for miscarriage once you’ve conceived. Recent studies have found evidence that the incidence of miscarriage in women with endometriosis is likely higher than in women who don’t have it. More research is needed in this area to understand the reasons behind these results.

If you have endometriosis, it may help to be aware that you could be at greater risk of miscarriage so that you can take extra measures to take care of yourself and avoid any other risk factors.

Generally, though, a miscarriage occurs when a fetus isn’t developing correctly. In these cases, there is nothing you can do to prevent it from happening.

If you experience any signs of a miscarriage, you should see your doctor immediately to determine what is happening, and whether or not you need any treatment. It’s entirely normal to have feelings of grief following a miscarriage, and your doctor should be able to give you information as to where you can find support.