Early embryonic morphology sonographically assessed and its correlation with yolk sac in missed abortion.

PURPOSE: To provide additional information about embryo morphology sonographic assessment and its correlation with yolk sac.

METHODS: A systematic study in 200 consecutive cases of missed abortion <10 weeks diagnosed by transvaginal ultrasound.

RESULTS: In 104 gestations of embryos with morphological abnormalities, 88 (84.6 %) were at least 1 week smaller than expected for gestational age and 16 (15.4 %) were the expected size. From 32 normal morphologic embryos, 7 (21.9 %) were at least 1 week smaller than expected for gestational age, and 25 (78.1 %) were the expected size (p < 0.005). Normal morphologic embryos are linked more frequently with normal yolk sac (62.5 %). Findings in anembryonic gestations (GD1) included an absent yolk sac (46.9 %) and a cystic yolk sac (25 %). Likewise, findings in GD2-3 embryos included more frequently a cystic yolk sac (42.9 %) and an absent yolk sac (32.5 %). GD4 embryos are associated with an echogenic yolk sac (40 %), a relatively small-hypoplastic- (40 %) and a relatively large-cystic- (20 %). In DI embryos, yolk sac appears cystic (62.5 %) or echogenic (37.5 %).

CONCLUSIONS: Our study proves the correlation between morphology of conceptuses and yolk sac appearance in cases of missed abortion.