<prompt> Earliest anomaly to be detected in ultrasound is:AnencephalySpina bifidaMeningoceleHorseshoe kidney  <response>: Earliest anomaly to be detected in ultrasound is Anencephaly as early by 10th week Anencephaly in Ultrasound: Acrania Loosely arranged brain parenchyma Frog Eye Appearance Figure: Frog eye sign and irregularly outlined brain patter protruding freely into amniotic fluid is seen, with absence of cranial vault. 