Sonographic markers of exencephaly at 9 + 3 weeks of gestation

Abstract

Following the introduction of transvaginal sonography, several first trimester diagnoses of the exencephaly anencephaly sequence have been reported, with the earliest being described at 10 weeks of gestation. We report a case with a high index of suspicion for exencephaly at 9 weeks and 3 days because of three sonographic features: the cranial pole of the embryo was smaller than the chest, the cranial pole bulged dorsally and the surface of the cranium was irregular. The diagnosis was confirmed by a repeat ultrasound examination at 11 + 4 weeks and by autopsy after termination of pregnancy.

First-Trimester Echogenic Amniotic Fluid in the Acrania-Anencephaly Sequence

“…8 Wellpreserved brain tissue is usually found until 10 weeks' gestation, and the diagnosis of acrania is rarely reported before this gestational age. 12 Closer contact of the fetus with the uterine wall usually starts from about 10 weeks, when substantial portions of the amnion are fused with the chorion. The fetal brain is then exposed to increasing mechanical trauma, resulting in progressive "rubbing off" of the brain tissue.…”

“…13 Several authors have described the firsttrimester features of acrania in isolated case reports, the spectrum of the disease ranging from almost a normal amount of brain tissue with poorly mineralized calvaria to disorganized brain tissue covered by a thin membrane. 10,12,14 However, in a large first-trimester sonographic screening study at 10 to 14 weeks' gestation, the diagnosis of anencephaly was missed initially in 26% of cases. 4 During audit, it became evident that the main reason for missing the diagnosis was the fact that well-preserved brains were present in several cases (exencephaly), and only the lack of cranial ossification could provide a clue for the diagnosis.…”

Fetal Anomaly Which is Exencephaly and Accompanying Omphalocele at First Trimester

“…But most of the cases are reported at the earliest in 10-14. gestation weeks. 4 Ultrasonographic findings of first trimester exencephaly; decreased size of the cranial region compared to the chest, irregularity of cranial surface, and amniotic fluid echogenicity. 16 Calvarial bones were not observed in the first trimester ultrasonography of our case but opholocele and normal brain tissue were observed.…”

“…12 The exencephaly is a rare congenital anomaly (spectrum of acrania-exencephaly-anencephaly) that occurs in the spectrum of the acrania and anencephaly. 4,11 Many factors play a role in the etiology of neural tube defects. Genetic transition was detected in studies when NTD seen with a syndrome.…”

Anenzephalie im 20-Schwangerschaftswochen-Screening - Wann ist der richtige Zeitpunkt für die frühe Diagnose?

“…SSW zeigen die Feten eher das Bild einer klassischen Anenzephalie [6]. Becker et al [21] stellten eine Exenzephalie in 9 + 3 SSW dar und bestätigten die Diagnose in 11 + 4 SSW. Bronshtein fand bei seriellen Ultraschalluntersuchungen im Verlauf des ersten Trimenons einer Schwangerschaft eine unauffällige Sonoanatomie bei 9 und 11 Schwangerschaftswochen.…”