Diagnostic Methods of Ectopic Pregnancy and Early Pregnancy Loss: a Review of the Literature

Abstract

This review article presents recent evidence on early pregnancy loss and ectopic pregnancy. In the light of recent evidence, the β-hCG discriminatory zone may be extended in clinically stable cases without evidence of bleeding. A possible cut-off is 4300 mIU/ml, which corresponds to when a sonographer should detect an intrauterine pregnancy. Embryonic demise can be confirmed when a transvaginal ultrasound finding shows no heartbeat in an embryo of more than 7 mm CRL, no embryo in a gestational sac having a mean sac diameter of more than 25 mm, or no appearance of an embryo within 7-10 days after the primary examination. These are considered definitive signs of embryonic demise. Suggestive signs of embryonic demise require closer monitoring of the pregnancy.

Keywords: early pregnancy loss; ectopic pregnancy; fetal demise; ultrasound; β-hCG.

Fig. 1

The diagnosis of early pregnancy summarized in a flow chart.

Fig. 2 a

and b  a Expanded amnion sign: transvaginal US of a small embryo surrounded by an amniotic sac. This sac is too big for the measured CRL. For early embryos, the CRL is proportionally related to the amnion diameter. This embryo should be approximately 10 mm in size, much larger than in this case (published with permission) . b Yolk stalk: an embryo (E) of a CRL < 5 mm and no cardiac activity. Although short, a yolk stalk (YSt) can be recognized separating the embryo from the yolk sac (YS), which indicates a more advanced gestational age than would have been concluded from the CRL alone (published with permission) .

Fig. 3

Retrochorial hematoma in the first trimester on lining the anterior wall of the uterus (marked by multiple white squares in the image – image provided by the authors).