People struggling with infertility are usually quick to turn to IVF. If that doesn't work, the detective work begins. Many women can be helped after the basic tests, but others need further diagnosis. One helpful method is to take tissue samples from the uterus, which can then be examined in more detail. This is called an endometrial biopsy. We're going to talk about what it is and when it can help you.

What is the endometrium?

If you've read a few articles about pregnancy, you've probably heard the term endometrium a few times. It describes the lining of the womb. This is the innermost layer of the womb. It varies in thickness depending on the time of the menstrual cycle. After your period, there is only a very thin layer that builds up over the next few weeks. Ovulation usually occurs halfway through the cycle in the ovary, and the egg takes about a week to reach the uterus. By this time, the lining of the womb has reached its maximum thickness. This provides the best conditions for the fertilised egg to implant successfully. If fertilisation has not taken place, implantation will not take place. In the last few days of your cycle, the blood vessels shrink and the endometrium is less supplied with blood. As a result, it slowly dies and is shed with the next period. After that, the lining of the womb starts to grow again. This whole process is controlled by hormones. If the cycle is disrupted, this can lead to fertility problems.

What is a biopsy?

You may have heard the word biopsy. A biopsy is a procedure in which a piece of tissue is removed from the body. The size of the biopsy sample depends on the reason for the biopsy and the organ being examined. However, the volume removed is usually small because a biopsy is always a diagnostic tool, not a treatment. The procedure is therefore usually as minimally invasive as possible. Again, this depends very much on the location of the biopsy. Often, tissue samples are taken during an endoscopy of the organ. If there is doubt about the nature of the disease during an operation that is already planned, samples may be taken during an open operation, but such operations are not done specifically for a biopsy. However, the uterus is very easy to access through the vagina, so it is very suitable for a biopsy.

Once the tissue samples have been taken, they are usually sent to a pathology laboratory. The doctors there will prepare them. This involves cutting larger samples into wafer-thin slices a few micrometres thick and staining them. There are many ways to do this, depending on what exactly you are looking for. Immunological methods can be used to specifically stain individual cell components or cell types. The preparations are then examined under the microscope. In addition, various hormonal activities can be tested in the biopsies. The pathologists can use the results to make a diagnosis and pass it on to the patient's gynaecologist.

Endometrial biopsy procedure

As mentioned above, taking a biopsy of the endometrium is relatively easy. To get better access to the uterus, the cervix needs to be opened slightly. This is done in the same way as a routine check-up. A curette is then inserted through the vagina into the uterus. This is a device similar to a spoon that is used to scrape away the lining of the womb.

The procedure takes about fifteen minutes. You will be given a local anaesthetic so you will not feel any pain. If you already feel pain or are very afraid of this type of procedure, you can have a general anaesthetic. In either case, you will be able to go home when you wake up. However, you should be aware that you are not allowed to drive after an anaesthetic, so plan to have someone pick you up or take a taxi.

If you are already pregnant, you should not have an endometrial biopsy. The endometrium is exactly where the baby will implant. A scrape can therefore lead to miscarriage or developmental problems. You can have an ultrasound scan before the biopsy to make sure you are not pregnant. There is no need to worry about fertility problems after a biopsy. As described above, the endometrium simply rebuilds itself in the next cycle and is fully functional again.

What can be tested with an endometrial biopsy?

In general, a biopsy is never the first step in the diagnosis of a disease. It is done when the basic tests have given abnormal results or have not provided the desired clarification.

A biopsy allows the cells in the tissue to be examined. This can show whether the endometrium has rebuilt properly or whether there are abnormal cells or cell arrangements. The latter can be an indication of polyps or endometriosis, but also plays an important role in the diagnosis of tumours.

Secondly, the hormonal activity in the tissue can be determined. This is of particular interest to women with cycle disorders and fertility problems.

When should biopsying be done?

Biopsy is not the method of choice for every gynaecological test. However, there are indications where it should be ordered. For example, in cases of unexplained infertility. In this case, it makes sense to investigate the cause of the infertility, especially if several IVF attempts have failed. If you have unexplained or abnormally heavy bleeding from the uterus or vagina, an endometrial biopsy may be carried out to check for endometriosis. If the ultrasound scan shows growths in the uterus, a biopsy is essential to determine the type of tumour and to guide further treatment.


Some fertility centres offer biopsies as part of endometrial scraping. This involves lightly scratching the endometrium in a similar way to the biopsy to stimulate blood flow. This is thought to increase the chances of successful implantation in the next cycle. However, there is no clear scientific evidence to support this. If you would like to know more about scratching, there is a blog article about it on this page.


On the other hand, the benefits of a biopsy can be great and may help to clarify your fertility problem. You should have a thorough discussion with your doctor before the procedure. In general, there is no need to be afraid of a biopsy as it is a routine procedure and is usually well tolerated by the donor.