[Ultrasonic diagnosis of exencephaly/anencephaly during the first trimester].

The paper deals with first trimester diagnosis of exencephaly. In association with first trimester sonographic and cytogenetic screening of chromosomal anomalies in 1145 examined pregnancies 2 exencephalic fetuses with normal karyotype were diagnosed. Exencephaly was characterized with the absence of normal echoes of the exocranium, the lateral ventricles, the chorioid plexus, the cerebral falx, and with the presence of deformed shape of the head and irregular, lobulated cerebral material with increasing volume at follow-up examination. Anencephalic fetuses were diagnosed subsequent to therapeutic abortion, since the uterine and cervical wall contractions eroded the fragile brain tissue during fetal expulsion. However, fetal brain was identified in abortion material in both cases providing evidence that exencephaly is an embryologic precursor of anencephaly.