In an abnormal pregnancy, the gestational sac may have a distorted nonovoid contour.
The lack of an echogenic rim helps to distinguish these cysts from the gestational sac seen with the intradecidual sign of an early IUP.
Adnexal ultrasound findings with a high positive predictive value (PPV) for ectopic pregnancy can be categorized into 4 groups: live embryo in an extrauterine gestational sac (PPV = 100%, Figure 11), adnexal mass with yolk sac or nonliving embryo (PPV close to 100%), complex or solid adnexal mass (PPV = 95%, Figure 12), and echogenic tubal ring/donut that is separate from the ovary (PPV = 90% to 95%, Figure 13).
23) In the authors' experience, if myometrium can be documented between the edge of the gestational sac and the endometrium, such that the endometrial stripe is clearly separate from the gestational sac, the ectopic pregnancy is likely interstitial in location.
4% when a mean gestational sac diameter of 16 mm was used as a cutoff and 0.
Vrees asked for a show of hands as to who uses a mean gestational sac diameter cutoff of 21 mm to define early pregnancy loss in the absence of both a yolk sac and embryo.
Large bleeds, defined as involving more than 2/3 the circumference of the gestational sac, are more likely to result in pregnancy failure (Figure 8).
24,25) An additional feature that can be helpful is the "interstitial line sign," representing a thin echogenic line extending from the endometrial canal directly to the gestational sac, representing the cornual segment of the endometrial canal or interstitial portion of the fallopian tube (Figure 10).
The gestational sac in a cervical ectopic pregnancy must be distinguished from a gestational sac passing through the cervix during an abortion in progress.
Looking at viable pregnancies that later miscarry, "we wondered if the bleeding around the gestational sac
was one of the reasons why these women were miscarrying," said Dr.
Implantation rate was calculated by dividing the number of gestational sacs
seen on trans-vaginal sonography by the number of embryos transferred.
The gestational sac
can be visualised as early as four and a half weeks of pregnancy.
Implantation rates, calculated as gestational sacs
per total number of embryo transfer, were 36% for cauterization, 24% for salpingectomy, and 7% for no surgery.
Minimum mode" reveals vasculature; while "inversion mode," which dims light structures and highlights dim ones, brings out fluid cavities and makes it possible to visualize such structures as the chambers of the heart and determine the number of gestational sacs
, he said.
1) In the sample of 120 women, abdominal imaging picked up all 116 gestational sacs
detected by vaginal ultrasound before the drugs were taken; it underestimated gestational age by 1.