Pregnancy with Ovarian Cyst

Pregnancy with ovarian cyst is the finding of an ovarian cyst or mass during pregnancy. It is common, and most are functional or benign, such as corpus luteum cysts, dermoid cysts, endometriomas and cystadenomas. A small number are malignant. It matters because torsion, rupture and cancer must be recognised and treated at the right time.

• Most functional cysts resolve by 16 weeks.
• Risk factors for complications: size above 6 cm, solid areas, ascites.
• Surgery is best done at 14 to 20 weeks if needed.

Most women have no symptoms. Others have pelvic pain, abdominal distension or pressure. Torsion or rupture cause sudden severe pain with vomiting.

• Mass may be felt in the pelvis or abdomen.
• Pain is unilateral and may radiate to the back.
• Differential diagnosis: corpus luteum cyst, dermoid cyst, endometrioma, cystadenoma, ovarian cancer, ectopic pregnancy, fibroid, appendicitis.
• Complications: torsion, rupture, haemorrhage, obstructed labour, preterm labour, malignancy.

The approach is ultrasound to classify the cyst, with magnetic resonance imaging for uncertain masses.

• Transvaginal and abdominal ultrasound: size, wall, septa, solid areas, ascites and Doppler flow.
• Simple unilocular cyst below 5 cm is likely functional; complex features such as solid papillary areas, thick septa or ascites raise concern.
• Magnetic resonance imaging without gadolinium where available.
• Tumour markers (CA 125, alpha fetoprotein, hCG) are raised in pregnancy and have limited value; lactate dehydrogenase may help.

The principle is observation for simple cysts, with surgery in the second trimester for large, complex, symptomatic or suspicious cysts.

• Supportive: reassure; avoid vigorous twisting; written warning symptoms; repeat scans.
• Pharmacological: paracetamol 1 g oral 6-hourly as needed (maximum 4 g in 24 hours); ceftriaxone 1 g IV single dose at surgery; morphine 2.5 to 5 mg IV titrated for severe pain; give enoxaparin 40 mg subcutaneous daily after surgery until fully mobile.
• Procedures: laparoscopic cystectomy or laparotomy at 14 to 20 weeks for cysts above 6 cm that persist, complex cysts, or suspected malignancy; emergency detorsion and cystectomy at any gestation for torsion; oophorectomy for malignancy.
• Special groups: women with suspected ovarian cancer need staging surgery and gynaecological oncology review; Rhesus negative women with bleeding or surgery give anti-D immunoglobulin 250 IU IM within 72 hours.
• Red flags: sudden severe pain, vomiting, fainting, fever above 38 degrees Celsius, rapidly growing mass, ascites.
• Follow-up: repeat scan at 12 to 16 weeks and 20 weeks; again at 28 weeks if the cyst persists; plan the delivery route from cyst size and position; postnatal scan at 6 to 8 weeks.