The establishment of ultrasonography in daily gynaecological and obstetric practice has increased the rate of diagnosis of ovarian cysts amongst pregnant women. Both assessment and management of ovarian cysts in pregnancy can be challenging. Although most cysts are functional in nature and a conservative approach can be employed, a small proportion will carry some malignant potential. Identifying which cysts can be safely managed expectantly and which necessitate surgical intervention, investigating possible cyst accidents, deciding on the timing and nature of intervention (fine needle aspiration versus cystectomy or even oophorectomy), the surgical approach (laparotomy versus laparoscopy) and balancing the risks and benefits for the mother and the fetus are just a few examples of the dilemmas that need to be addressed, ideally within a multidisciplinary team-based environment.

Pelvic masses in pregnant women are rare. However, the incidence of pelvic masses is likely to increase due to the combination of the delay in childbearing and the routine practice of ultrasound during pregnancy follow-up. Pelvic masses can have a gynecological or nongynecological origin. Gynecological pelvic masses can originate in the adnexa or the uterus, mainly in the form of adnexal cysts or myomas. Most pelvic masses are asymptomatic, and diagnosed incidentally during routine first-trimester ultrasound. When symptoms are present, the most common one is abdominal pain. The aim of this chapter is to summarize the published literature on gynecological pelvic masses in pregnant women, focusing on adnexal cysts and myomas, as well as the possible symptoms, complications, and treatment.

A 40-year-old woman, gravida 3, para 3, with last menstrual period two weeks ago presents for evaluation of a palpable pelvic mass. She reports noticing a slow increase in her abdominal distention over the last four months; however, she denies abdominal pain. She denies any bowel or bladder dysfunction. She is sexually active and denies dyspareunia. Her sexual partner has had a vasectomy. She denies a personal history of breast cancer and denies any family history of breast, ovarian, or colon cancer. Her medical history is significant for anxiety. She has no past surgical history. She is currently taking citalopram. She has no know drug allergies.