A 33 year old woman presents at 8 weeks of her first gestation complaining of cramping lower abdominal pain for 2 days, in a background of vague pelvic pain for the last week.

She received in-vitro fertilization (IVF) to become pregnant, following 3 years of primary infertility attributed to asthenozoospermia in her husband. A total of 4 embryos were implanted.

A transvaginal ultrasound scan performed at 6 weeks of gestation revealed a single live intrauterine pregnancy, while a serum beta-hCG assay was found to be 10,200 mIU/ml