Using the International Reference Preparation standards, if the HCG level is at least 1,000 mIU/mL, the gestational sac
should be identifiable.
All women had conventional two-dimensional measurements of gestational sac
diameter (GSD) and crown-rump length (CRL) and three-dimensional volumetric data of the gestational sac
(GSV), yolk sac (YSV) and embryo (EV) recorded.
By 5 weeks gestational age, a more clearly defined gestational sac
should be observed with a double decidual sac sign present.
Cornual pregnancy describes the presence of an eccentrically located gestational sac
surrounded by a thin rim, specifically <5 mm of myometrium (2).
Given the inherent inter--and intraob-server variation in ultrasound measurements, he and his colleagues favor more conservative criteria for the definitive diagnosis of early pregnancy failure: a crown-rump length cutoff of greater than 7 mm instead of 5 mm, and a mean gestational sac
diameter cutoff of more than 25 mm.
The yolk sac is the first structure able to be visualized within the early gestational sac
(chorionic sac), usually by the time the mean gestational sac
diameter (MSD) is 8-10 mm (Figure 4).
Only approximately 2% of ultrasounds done for possible ectopic pregnancy will show a gestational sac
with a yolk sac or fetal pole visible outside the uterus, and thus be diagnostic, Dr.
Pelvic ultrasound showed no abnormalities of the fetus, gestational sac
, or uterus.
According to the report, an ultrasound which was carried out on January 21, 2013 on the pregnant woman, showed an endometrial gestational sac
without foetal elements.
The lack of a gestational sac
or chorionic villi within the specimen made an ectopic pregnancy or GTN unlikely.
Omental covering of the gestational sac
is common and may create a surrounding layer with very similar ultrasound appearance to the uterine wall, and the empty uterus can easily be missed on a routine transabdominal scan.
Three of the 29 did not return for follow-up; of the 26 who did, none had a gestational sac
or a continuing pregnancy.