Amnion Rupture Sequence

Abstract

The amnion rupture sequence is a rare condition occurring early in pregnancy, resulting in complex fetal anomalies by disrupting normal embryonic development. The prevalence of amnion rupture sequence is reported to be 1.16 in 10,000 live births. This article explores the uncommon case of early amnion rupture leading to fetal encephalocele, suspected in the first trimester. Despite the variable and intricate nature of anomalies associated with this condition, cranio-facial and abdominal defects are frequently observed. Genetic testing was conducted, with normal results supporting our theory of amnion rupture. The patient decided to terminate the pregnancy, and the anatomopathological results confirmed the findings. This article discusses the diagnostic challenges, emphasizing the importance of timely identification through advanced imaging techniques.

Keywords: amnion rupture sequence; encephalocele; neural tube defect.

Figure 1

On ultrasound examination, we found a fetus with a CRL of 56.1 mm corresponding to 12 weeks and 1 day, a nuchal translucency of 1.4 mm and an abnormal posterior fossa of the fetal brain. In mid-sagital view of the fetus, we could not demonstrate a normal brainstem to brainstem-occipital bone ratio. The intracranial translucency was not visible. (a) Mid-sagital view of the fetal profile; the amniotic membrane was wrapping the fetus, and the retroamniotic space was largely increased. (b) Transvaginal (TV) ultrasound scan demonstrating the occipital bone defect and the herniation of the fetal brain tissue throughout it.