Intraamniotic bleeding and gastric pseudomass in fetus at 21 weeks gestational age, 2 weeks after transplacental amniocentesis

(A) Transverse transabdominal sonogram shows echogenic particles floating in amniotic fluid (arrow) that were not present before amniocentesis. Until third trimester, echogenic particles in amniotic fluid should raise possibility of bleeding. Later in pregnancy, particles are most commonly the result of shed epithelial cells (vernix caseosa).
(B) Transverse sonogram of fetal abdomen shows echogenic material (arrow) in stomach that results from fetus swallowing echogenic blood particles that resulted from recent amniocentesis. Gastric pseudomasses resolve on follow-up examination. To our knowledge, no gastric neoplasms have been reported on prenatal sonography.