Ovarian cysts are fluid-filled sacs on an ovary. Finding an ovarian cyst during pregnancy can be a source of worry. Many women discover them incidentally during prenatal imaging. Understanding their nature and implications during pregnancy provides clarity.
Understanding Ovarian Cysts During Pregnancy
Ovarian cysts are common during pregnancy (0.2% to 5.4% incidence). Many are “functional cysts,” forming as a normal part of the menstrual cycle and early pregnancy. The most common type is the corpus luteum cyst, which develops after an egg is released. This cyst produces progesterone, supporting early pregnancy until the placenta takes over. These cysts are harmless, painless, and often resolve by the second trimester.
Beyond functional cysts, other benign ovarian cysts can be found during pregnancy, including dermoid cysts (also known as teratomas) and endometriomas. Dermoid cysts contain tissues like hair, skin, or fat. Endometriomas, sometimes called “chocolate cysts,” are associated with endometriosis and are filled with old blood. Most non-functional cysts discovered during pregnancy are benign.
How Cysts Can Affect Pregnancy
While most ovarian cysts during pregnancy are asymptomatic, some can cause discomfort or complications. Common symptoms include pelvic pain or pressure, sharp or dull and localized to the cyst’s side. Bloating and abdominal fullness are also possible. These symptoms may sometimes be mistaken for typical pregnancy discomforts.
More severe, though rare, complications can arise. Ovarian torsion occurs when the ovary, enlarged by a cyst, twists around its blood supply. This causes sudden, excruciating pain, often with nausea and vomiting, requiring immediate medical attention. Another complication is cyst rupture, where the cyst bursts. This can lead to sudden, severe pain, internal bleeding, or infection. Hemorrhagic cysts, filled with blood, are a common type that can rupture. Severe complications are uncommon, and most ovarian cysts do not harm the developing fetus.
Diagnosis and Management of Cysts in Pregnancy
Ovarian cysts are frequently discovered incidentally during routine prenatal ultrasounds, especially in the first trimester. Ultrasound is the primary diagnostic tool, assessing the cyst’s size, shape, and internal characteristics (fluid-filled, solid, or mixed). If initial ultrasound findings are unclear or suggest a more complex cyst, MRI may be recommended, considered safe during pregnancy.
For most benign, asymptomatic cysts, watchful waiting is the general management approach, involving close observation. Regular follow-up ultrasounds monitor the cyst’s size and appearance, as many functional cysts resolve. Pain medication may manage symptoms. Surgical intervention (cystectomy) is reserved for persistent, symptomatic cysts, those with suspicious features, or complications like torsion or rupture. If surgery is necessary, it is often performed during the second trimester (16-23 weeks gestation) to minimize risks to the pregnancy.
Ovarian Cysts and Childbirth
An ovarian cyst usually does not impact the birthing process. For most women, vaginal delivery remains a safe and viable option. In rare instances, a large pelvic cyst might obstruct the birth canal (previa obstruction). A C-section may be necessary to ensure safe delivery for mother and baby.
Sometimes, an ovarian cyst may be discovered or managed during a planned C-section for other reasons. If a cyst could complicate delivery or requires removal, it can often be addressed during the C-section. While the size and location of a cyst can influence delivery decisions, most ovarian cysts do not necessitate changes to the planned childbirth method.