^{ULTRASOUND FINDINGS WITH ABNORMAL PREGNANCIES}

Empty gestational sac without fetal pole. Need three views (length, width and height) to calculate MSD. An empty gestational sac with a MSD of ≥25 mm is diagnostic of an anembryonic pregnancy.  Early pregnancy loss occurs in approximately 10-20% of clinically recognized pregnancies

Note that this gestational sac with fetal pole is not intrauterine (no cervix is seen in the same plane). Ectopic pregnancy occurs in approximately 1-2 % of pregnancies, and is even more uncommon among pregnant people seeking abortion (0.25%) (Duncan 2020).

Longitudinal view of the uterus. Note the presence of anechoic (dark) fluid in the posterior cul-de-sac. This may be a finding consistent with blood from an ectopic pregnancy or uterine perforation

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Image of complete mole (no embryo). A complete mole generally has a cystic intrauterine mass with no distinct gestational sac with yolk sac or fetal pole. Often has a swiss cheese, snowstorm, or moth-eaten appearance on US. Consider referral for inpatient management > 12-week size  due to increased bleeding risk. Gestational trophoblastic disease occurs in approximately 0.1% of pregnancies

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Fibroid uterus

Uterine fibroids are a common pelvic tumor that may enlarge or distort the cervix or uterine cavity, presenting technical difficulty. US can help identify the size, location, and orientation to the pregnancy

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^{Images AIUM 2018 and 2020}