Does the mean sac diameter (MSD) double every 48 hours?
*No*. For a gestational age <8 weeks, the B-hCG doubles every 48 hours. The MSD increases ~2.2 mm per 48 hours.
By what week in pregnancy do corpus luteal cysts normally regress?
What is your recommendation to this woman regarding her lab values and ultrasound findings?
She has a positive B-hCG so gestational tissue is located somewhere.... but that little fluid collection is a poor candidate for a normally-progressing gestational sac. If she is asymptomatic, then a close interval follow up ultrasound and B-hCG (~7 days) should reveal the gestational sac and how the pregnancy is progressing. If symptomatic, then referral to OB/GYN for discussion of management is appropriate.
- 9 x 7 x 1 mm intrauterine fluid collection in the lower portion of the uterine cavity
- anechoic, oblong, and with angular margins
- located in the lower uterine cavity
- slightly eccentrically located
- no evidence of a double decidual layer
- no definite intrauterine pregnancy (IUP) is identified
- thickened endometrium
- prominent right ovarian cystic lesion is compatible with a corpus luteum
- no free fluid in the cul-de-sac