You may have a niche, or you may want to know more about it. This brochure will explain what a niche is, the associated symptoms, and what treatments are possible. In addition, we have a separate leaflet on niche removal by keyhole surgery.
What is a niche?
A "niche" is a cavity-shaped scar in the uterus after a C-section. If we do an ultrasound on all women after a C-section, we will see a niche in 60% of them and even a large niche in 25% of them. We call a niche "large" when more than half of the uterus's muscle wall consists of a niche. Niches are therefore very common, and in the vast majority of cases, niches do not cause any symptoms and therefore do not require treatment. Unfortunately, we don't yet know that much about the cause of niches. So far, research has shown that it does not seem to have much to do with how the Caesarean section was performed but possibly more to do with poor wound healing. We see this more often with, for example, adenomyosis. Adenomyosis is a disease in which the endometrium partly grows in the uterus's muscle wall and gives complaints of heavy menstrual blood loss and painful periods.
What symptoms can cause a niche?
Previous research shows a relationship between different complaints and niches. The most common complaints seem to be:
- Spotting: interim blood loss between periods. This can be bright red blood loss or brown discharge.
- Painful menstruation: Many women have increased pain during menstruation since a cesarean section, and there seems to be a relationship with the niche. However, there are also many other reasons for painful periods (e.g., adenomyosis).
- Subfertility: or a desire for children that has not been fulfilled for more than a year. We do not (yet) see a direct relationship with miscarriages. Still, we do see a direct connection with a delayed pregnancy.
What treatments are available?
The treatment of a niche depends mainly on the complaints and the muscle wall that is still present above the niche. In our opinion, a niche without complaints should not be treated, even if a woman wants to become pregnant. The treatments for the complaints caused by a niche include a wait-and-see policy, hormonal therapy (e.g., the pill or a hormone-containing IUD), or surgery.
The surgeries out there for treating a niche are:
- A hysteroscopic niche resection: a thin viewing tube is used to look into the uterus through the vagina. The blood vessels in the niche can then be cauterized, and the niche is made slightly flatter so that blood can flow out more easily. As a result, the niche is actually made slightly larger.
- A laparoscopic niche resection: the niche is removed from the uterus with keyhole surgery through the abdominal cavity. After this, the uterus is repaired with stitches.
- Removing the uterus is sometimes suggested as the last option in patients without a desire to have children.
Not all treatments are possible for all niches. For example, a relatively shallow niche with a thick muscle layer above cannot have a laparoscopic niche resection. Likewise, a deep niche with a thin one above cannot have a hysteroscopic resection. Also, all treatments have their risks, which you can educate yourself about at the consultation.
All treatments are performed in different studies. We believe it is important to embed this care in research to evaluate our expertise and improve the technique. In addition, we also learn about the long-term effects of the procedure that we make known in international scientific journals.
What if I get pregnant, and I have a niche?
We believe that you can safely conceive with a niche. There is a small chance (1:1800) that a pregnancy will go into a niche. This is called a niche pregnancy. Sometimes it is necessary to terminate this pregnancy or receive other treatment for it. Because this is so rare, we do not treat women with surgery to prevent it. However, we do advise women with a niche to get an ultrasound relatively early (around 6 weeks of pregnancy) to assess whether the pregnancy is in the right place. Another concern may be that the niche is weak in the uterus, and the uterus is no longer firm enough. This could lead to the uterus tearing open (a uterine rupture). To date, there is no evidence that a niche can lead to a spontaneous uterine rupture in pregnancy. Depending on the size of the niche, a person may be at increased risk of this during labor. In some women, we recommend a planned cesarean section. This is certainly not the case for everyone, so be sure to be well-informed by your gynecologist. We also have a separate leaflet for women who want to become pregnant with a niche.
Is a niche dangerous?
No, a niche is not dangerous. It will not become cancerous and will often not grow larger from a certain period after the cesarean. However, it can cause many very unpleasant symptoms. The risks of pregnancy and a niche were briefly discussed above.
What else do I need to know?
There is a lot of research being done on niches worldwide, and new knowledge is emerging all the time. Some information in this leaflet may already be out of date. Therefore, please discuss your questions carefully with your doctor. At the Amsterdam UMC we are currently conducting a number of studies into the treatment of niches. We may ask you to participate in this. This will help us enormously in providing better advice to women in the future.
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