Current guidelines state that absence of a fetal pole with a mean sac diameter (MSD) of >25 mm is diagnostic of anembryonic pregnancy, but a MSD of 16-24 is certainly suspicious, and given the patient's stated LMP, this is even more suspicious. This is at this stage, a pregnancy of uncertain viability (PUV), with poor prognostic factors. It requires followup with serial bHCG and a repeat ultrasound.

Follow-up ultrasound demonstrated disappearance of the gestational sac with a decreased beta hCG, confirming a failed early pregnancy.