Surgical excision of endometriosis and endometriomas is an essential of therapy for this condition especially to treat pelvic pain. However, increasing research has shown that surgery for ovarian endometriosis (endometriosis) can be a double-edged sword.

When surgery is done to remove endometriosis, it is typically to treat persistent pelvic pain. It can also aid in performing various fertility treatments such as intrauterine insemination (IUI) or in-vitro fertilization (IVF). To remove these endometriosis, drainage is not enough since they often fill up again within a year after drainage. The best approach is to completely remove the cyst. This requires cutting into the ovary which can have a negative effect on a woman’s egg count.

The data on endometriosis surgery

Numerous studies have observed this. In one study, the removal of endometriosis led to a 48% drop in ovarian reserve. This drop persisted for six months after surgery. One interesting observation is that patients that underwent surgery for non-ovarian forms of endometriosis did not have any noticeable decline in their ovarian reserve. Another study looked at IVF outcomes in women who had endometriomas removed. Compared to the group that did not undergo surgery, the surgery group needed more medication to stimulate follicle growth and had fewer eggs obtained. These two studies comprise only a small portion of the data noting a negative effect on ovarian endometriosis surgery on ovarian reserve.

Due to this well described drop in ovarian reserve with endometrioma excision, patients with this form of endometriosis may benefit from egg freezing prior to surgery being done. Once the ovarian reserve drops, it cannot be reclaimed. Egg freezing prior to surgery could help minimize this drop on the future chance of conception.

In summary, endometriosis surgery in-general only affects ovarian reserve if there is endometriosis present on the ovary i.e. and endometrioma. If the endometrioma is not very large, does not cause pain, and will not interfere with any fertility treatment, it is best left alone.

This content was written by Alexander M. Kotlyar, MD, FACOG. Director of Resident Education at Genesis Fertility.