Lack of cardiac activity-lack of cardiac activity in an embryo indicates death; however, cardiac activity is often not visualized in
embryos less than 4 mm in size. 11 in doubt a repeat examination should be undertaken
Yolk sac characteristics.-Absence of yolk sac on TVS when GS diameter is 8 mm or more indicates pregnancy failure. Yolk sac calcification is associated with a poor prognosis. An abnormal shaped yolk sac and lack of growth of the yolk sac are further signs of pregnancy failure
Gestational sac features- On TVS, MSD of >8 mm without a yolk sac or >20 mm (mean sac diameter) without an embryo usually indicates pregnancy failure. A distorted GS shape, decidual reaction less than 2 mm, absence of a double decidual sign, weakly echogenic decidual reaction and low position of GS within the uterine cavity arc other ancillary signs of an abnormal pregnancy.
Abnormal amnion-A collapsing amnion, an amnion with irregular margins and when amnnion is seen with no visible embryo indicate pregnancy failure. Enlarged amniotic cavity or a yolk sac diameter more than 2 standard deviations above the mean when compared with mean GS diameter arc associated with poor outcome
Fetal bradycardia-the normal heart rate at 5—6 weeks is 100/mm, rising to 140/mm at 8—9 weeks. A heart rate below 85/mm at 5—8 weeks is said to be a poor prognostic sign
Oligohydramnios-OH in the embryonic period indicates a poor outcome. UnusuaIIy low scrum BhCG for the GS size has been described as a predictor of abnormal pregnancy in 65%