Final answer:
The symptoms and ultrasound findings suggest an ectopic pregnancy. This is due to the patient experiencing pelvic pain, the ultrasound revealing an anechoic sac lacking a double decidual sac sign, and the presence of cul-de-sac fluid. Additionally, the history of pelvic inflammatory disease contributes to the likelihood of an ectopic pregnancy.
Step-by-step explanation:
Based on the symptoms and ultrasound findings, this case is most suspicious for an ectopic pregnancy. An ectopic pregnancy occurs when a fertilized egg implants outside of the uterus, usually in the fallopian tubes. Pelvic pain is often associated with ectopic pregnancies, and the ultrasound findings support this diagnosis. The anechoic sac lacking a double decidual sac sign usually indicates an ectopic pregnancy. The history of pelvic inflammatory disease increases the risk. Lastly, cul-de-sac fluid (fluid found in the rectouterine pouch) is present in both ectopic pregnancies and other conditions, but in combination with the other factors it points to an ectopic pregnancy.
Learn more about Ectopic Pregnancy