Sonographic markers of exencephaly below 10 weeks' gestation

Abstract

We report two cases of exencephaly diagnosed by transvaginal ultrasonography at 8 weeks 4 days and at 9 weeks 3 days of gestation. Both cases presented an irregular cephalic pole, and, in the case seen at 8 weeks 4 days, brain vesicles were also absent, whereas in the case seen at 9 weeks 3 days, the midline echo was indistinguishable with disorganized choroid plexuses. In both cases, anencephaly was evident at 11 and 12 weeks' gestation and the postmortem confirmed the diagnosis.

Exencefalia: diagnóstico prenatal y reporte de caso

“…Con respecto al diagnóstico de exencefalia, se realiza mediante ecografía a partir de la 8-9 semana de gestación por la observación de la irregularidad del polo cefálico. En la 11. a semana se hace evidente la falta de la cubierta ósea de la bóveda craneal, defecto conocido como imagen en batracio [7][8][9][10][11] .…”

Amniotic band syndrome associated with exencephaly: A case report and literature review

“…Some studies have shown that it is an embryological precursor of anencephaly, resulting from the degeneration of the unprotected brain tissue affected by mechanical and chemical trauma when exposed to the amniotic fluid. [712]…”

Prenatal diagnosis of cranial vault defects

“…We read with interest the report on sonographic markers of exencephaly below 10 weeks' gestation (Machado et al, 2005). However, we think that there is confusion and not well-defined diagnosis between different types of cranial vault defects.…”

“…Diagnosis of cranial bone defects can be established by ultrasonography early in the second trimester of pregnancy after mineralisation of the skull bones has been completed, even if a prenatal diagnosis in the first trimester is possible as reported (Machado et al, 2005). Machado et al (2005) have not well-defined the type of cranial vault defects, in fact in both cases, prenatal scan demonstrated the absence of cranial vault and postmortem examination in the presence of anencephaly, but no histological examination was made to demonstrate the level of cerebral tissue degeneration or the exact diagnosis of exencephaly like that reported in the article title.…”