Worm Sign: A possible first‐trimester sonographic marker for intracranial haemorrhage resulting in significant cortical disruption

Fetal intracranial haemorrhage (ICH) is a pathophysiological process involving haemorrhagic and hypoxic–ischaemic insults resulting in antenatal brain damage. Insults to the central nervous system are usually not detected until the second or third trimester. In this case presentation, we present a possible prenatal ultrasound marker, ‘worm sign’, representing cortical disruption secondary to suspected ICH at 13 weeks’ gestation. According to current literature review, this is one of the first cases of ICH, diagnosed in the first‐trimester and highlights the importance of early neurovascular and structural evaluation of the fetal brain at the time of first‐trimester ultrasound screening.