Is an Ovarian Dermoid Cyst Dangerous During Pregnancy?

Finding out you have an ovarian dermoid cyst (also known as a mature cystic teratoma) during pregnancy can be frightening. However, these cysts are almost always benign (non-cancerous), and the vast majority of women with them go on to have healthy pregnancies and babies ^[1]. In many cases, the cyst is discovered accidentally during a routine ultrasound.

While having a dermoid cyst during pregnancy is generally safe, the physical changes your body goes through as the uterus grows can increase the risk of certain complications, such as the ovary twisting (torsion) ^[2]. Your care team will carefully monitor the cyst to protect both your health and your baby’s health.

Monitoring Your Cyst During Pregnancy

Most typical-appearing, asymptomatic ovarian dermoid cysts can be safely observed throughout your pregnancy ^[1]. Because these cysts generally do not disappear on their own, your doctors will use individualized ultrasound monitoring to keep an eye on the cyst’s size, appearance, and location ^[3], and will formulate a plan to re-evaluate it after you deliver.

• Size and Appearance: Dermoid cysts naturally contain solid materials like fat, hair, or calcifications ^[4]. While malignant (cancerous) transformation is very rare ^[5], doctors look for specific suspicious changes—such as new, irregular solid nodules or abnormal blood flow—that might require further evaluation with an MRI or a specialist referral ^[6][7].
• Observation: Cysts larger than 5 centimeters have a slightly higher risk of persisting or causing complications, but size alone does not mean you automatically need surgery ^[8][9]. If the cyst is not causing symptoms and does not look suspicious, observation is usually the safest path ^[1].

Because managing a cyst during pregnancy requires balancing maternal and fetal health, your care will likely involve a team approach. This team may include your obstetrician, a maternal-fetal medicine specialist (an expert in complex pregnancies), and a gynecologic surgeon ^[10].

Will the Cyst Affect My Delivery?

Most women with a dermoid cyst can still plan for a vaginal delivery ^[11]. A cesarean delivery (C-section) is typically only recommended if the cyst is very large or sits very low in the pelvis, physically obstructing the birth canal, or if you need a C-section for standard obstetric reasons ^[12].

Possible Complications and Risks

While many women experience no issues, the growing uterus can shift the position of the ovaries, which can lead to complications.

Ovarian Torsion

The most common acute risk is ovarian torsion, which occurs when the ovary twists on its supporting ligaments, cutting off its own blood supply ^[13].

• Torsion is more common with larger cysts and most frequently happens during the first or second trimester of pregnancy ^[12][2].
• Your personal risk varies based on the cyst’s size and position. For context, in one specific study of pregnant women with dermoid cysts, about 10% experienced torsion, though this does not represent a universal individual risk ^[1].
• Torsion is a time-sensitive emergency that requires urgent medical assessment ^[14].

Cyst Rupture

Though uncommon, a dermoid cyst can leak or rupture. Spilling the cyst’s irritating contents into the abdomen can cause chemical peritonitis (severe, painful inflammation of the abdominal lining) ^[15][16]. Suspected rupture requires prompt medical evaluation to determine if surgery is necessary ^[15].

When Is Surgery Needed?

Most dermoid cysts will not require surgery while you are pregnant, and elective removal is usually deferred until after your baby is born. However, surgery may be necessary in certain situations.

• Planned Surgery: If a cyst is extremely large, appears highly suspicious on imaging, or is causing significant, persistent discomfort, your doctors might recommend removing it during pregnancy. If this surgery is medically indicated but not an emergency, it is often planned for the second trimester ^[17][18]. Both surgery and anesthesia carry risks (such as preterm labor or pregnancy loss), but delaying necessary treatment also carries risks. Your team will carefully weigh these factors ^[18].
• Emergency Surgery: If you experience a complication like torsion or a severe rupture, emergency surgery may be required to resolve the issue and attempt to preserve the ovary (though the ovary cannot always be saved) ^[19]. Emergency surgery should not be delayed solely because of gestational age ^[17]. When performed by an experienced team, necessary emergency surgery can be done safely ^[1][20].

When to Seek Urgent Medical Care

Because ovarian torsion and cyst rupture require immediate evaluation, it is crucial to know the warning signs. Keep in mind that a reassuring ultrasound does not guarantee torsion won’t happen, and torsion pain can sometimes be intermittent (coming and going). Go to maternity triage or the nearest emergency room if you experience:

• Sudden, severe, or worsening pelvic or abdominal pain (especially if it is on one side) ^[2][15]
• Nausea and vomiting accompanied by pain ^[21][13]
• Faintness, dizziness, or a fever
• A rigid or extremely tender abdomen ^[16]
• Pregnancy warning signs, such as heavy vaginal bleeding, leaking fluid, regular contractions, or reduced fetal movement

New abdominal pain during pregnancy can have many causes, so you should never try to self-diagnose ^[22]. Always have a plan in place with your doctor so you know exactly where to go and who to call if these symptoms occur.