Decidualized endometrioma: an endometrioma that contains decidualized tissue that may be transformed during pregnancy. The solid areas of these masses may demonstrate significant vascularity and can appear similar to that seen in ovarian tumors.
Physiologic masses: those benign conditions that can be seen during pregnancy but typically regress spontaneously.
Sonography of the pregnant patient can reveal a wide variety of conditions, whether they cause acute discomfort or are asymptomatic. The greatest benefits of sonography over other diagnostic modalities in such a patient include its safety, low cost, and ability to localize and characterize pathology.
Gravid and nongravid women alike can be affected by uterine fibroids, dermoid cysts, physiologic cysts, and neoplasms. These can present as abdominal emergencies even though symptoms of pain and bloating can easily mimic normal discomforts of pregnancy. Imaging of the pregnant woman is most accurately and intuitively interpreted in the first trimester, before the growing uterus shifts abdominal anatomy. At any gestational age, sonography remains a superior diagnostic modality to distinguish the benign from the potentially dangerous without the harms of radiation and provides aid in management and therapeutic planning.
For many women, the sonographic examinations performed during pregnancy may be their first imaging studies. Previously asymptomatic or small pathology hidden to palpation may reveal itself to sonography and impacts subsequent clinical decisions regarding the pregnancy. Incidental masses may require prompt treatment, alter the labor and delivery plan, or necessitate further imaging. Recent joint guidelines on obstetrical sonography published by the American College of Radiology appropriately reflect the need for a comprehensive first trimester sonogram that includes the “uterus, cervix, adnexa, and cul de sac region” along with the gestational contents.1 This ensures that any poorly localized symptoms are not mistaken for the normal discomforts of pregnancy.
Undetected nonobstetrical abnormalities can cause significant complications despite their frequently benign cytology. The hormonal effects of pregnancy and increasing uterine girth can cause leiomyomata to enlarge, cysts to rupture, adnexal masses to undergo torsion, and cancers to grow. Early identification of abnormalities in the first trimester facilitates surgical treatment, if necessary, during the second trimester. At that time, risk of spontaneous abortion and preterm labor are lowest, and surgical exposure remains adequate. Though smaller incidental masses with benign sonographic characteristics are amenable to observation, surgical intervention is typically initiated for those that are larger (usually >7 cm in diameter), undergoing torsion, and/or suspicious for malignancy.2 Sonography can be used to accurately differentiate between the architectural patterns of benign and malignant masses and to determine which would be associated with an increased risk of ovarian torsion.3-6
Identification of incidental findings on transabdominal obstetrical sonography, inability to visualize the adnexa or cervix, or examination of an obese patient may obligate further ...