BACKGROUND: During the second trimester of pregnancy, the presence of free-floating particles in the amniotic fluid on ultrasonography has been associated with aggregates of cells or fetal blood and with unexplained elevation of maternal serum alpha-fetoprotein and the later development of abruptio placentae and fetal distress. During the third trimester, particulate amniotic fluid is thought to represent meconium or vernix. CASES: An unusual, ultrasonically dense appearance of the amniotic fluid was noted prior to 18 weeks of pregnancy in two asymptomatic women who carried exencephalic fetuses. In both cases, prenatal evaluation of the amniotic fluid suggested that the free-floating particles were due to the presence of blood. CONCLUSION: A detailed ultrasonographic evaluation should be undertaken should dense amniotic fluid be detected early in pregnancy because this sign may help in the early diagnosis of fetuses with congenital malformations likely to bleed.
BACKGROUND: During the second trimester of pregnancy, the presence of free-floating particles in the amniotic fluid on ultrasonography has been associated with aggregates of cells or fetal blood and with unexplained elevation of maternal serum alpha-fetoprotein and the later development of abruptio placentae and fetal distress. During the third trimester, particulate amniotic fluid is thought to represent meconium or vernix. CASES: An unusual, ultrasonically dense appearance of the amniotic fluid was noted prior to 18 weeks of pregnancy in two asymptomatic women who carried exencephalic fetuses. In both cases, prenatal evaluation of the amniotic fluid suggested that the free-floating particles were due to the presence of blood. CONCLUSION: A detailed ultrasonographic evaluation should be undertaken should dense amniotic fluid be detected early in pregnancy because this sign may help in the early diagnosis of fetuses with congenital malformations likely to bleed.