<prompt> Hydrocephalous is detailed best antenately by -X-ray abdomenAmniocentasisClinical examinationUltrasonography  <response>: Ans-DUltrasound Ref Williams Obstetrics, 21st,p. 1119-1120.The best method for the diagnosis of hydrocephalus prenatally is ultrasound.On ultrasound, the excess fluid is reflected by ventriculomegaly. 