A cyst is defined as a sac or pocket of tissue which is filled with air, pus or fluid. An ovarian cyst simply refers to a cyst that is found on or within an ovary. Ovarian cysts during pregnancy are common and rarely pose any risk to the mother or the fetus. They are often considered to be benign and usually go away on their own within several weeks to a couple of months. However, if they become painful or do not dissipate naturally, intervention may be necessary.
Causes of Ovarian Cysts During Pregnancy
Most cysts form as a result of a breakdown in the ovulation process. Because of this, ovarian cysts during pregnancy typically do not actually form during the pregnancy, but are likely to be present beforehand. Because cysts can take weeks to disappear, it is possible to have one form before you know you are pregnant and remain or continue to grow during early pregnancy. There are many causes of ovarian cysts, but the two most common causes are:
- Follicular cyst: A follicle is the fluid filled sac which contains the egg to be released during ovulation. A follicular cyst forms when a follicle becomes larger than normal during a menstrual cycle and does not open to release the egg.
- Luteum cyst: After an egg is released from the follicle, tissue begins to form within the ovary. When a pregnancy does not occur after ovulation, the tissue breaks down and disappears until the next cycle. A luteum cyst forms when this tissue fails to break down and instead, the ovary fills with fluid or blood.
Symptoms of Ovarian Cysts during Pregnancy
Most ovarian cysts during pregnancy go unnoticed and typically go away on their own, which means symptoms are rarely experienced. Because there may not be any symptoms, cysts are most frequently diagnosed during a routine ultrasound. For cysts that do not go away or might grow at a quicker rate, pain in the abdomen or in the area of the ovary may be felt. When this symptom is present, it is often due to more severe complications with the ovarian cyst such as:
- Rapid growth or stretching of the cyst
- Bleeding in to the cyst
- Rupturing of the cyst
- Twisting of the cyst around its own blood supply
Treatment of Ovarian Cysts during Pregnancy
Treatment for an ovarian cyst during pregnancy depends on the type of cyst, its origin and the time frame in which it is diagnosed. Because most ovarian cysts are considered harmless and go away on their own, treatment is typically not needed. But for women who are pregnant and have a cyst that is painful or will not go away, surgery may be necessary. If this is the case, most doctors will wait until the woman is half way through her pregnancy to prevent chances of a miscarriage. If surgery does become necessary, there are two procedures likely to be used, both of which are performed under general anesthesia:
- Laparoscopy: This procedure is used for smaller, benign cysts. During this procedure, a small incision is made directly above or below the navel, and a small telescope-like instrument is used to guide the surgeon to the cyst. This is considered a mild procedure and the patient can go home the same day.
- Laparotomy: This procedure is used for larger and potentially cancerous cysts. During this procedure, larger incisions are made in the stomach to remove the cyst. The cyst is then tested for cancer. This procedure is a little more invasive and the patient may stay at the hospital for two or three days.
Compiled using information from the following sources:
Smith, R. P. (2008). Netter’s Obstetrics & Gynecology (2nd ed.). Philadelphia, PA: Saunders.
Women’s Health, womenshealth.gov/publications/our-publications/fact-sheet/ovarian-cysts.html