“…An elevated amniotic fluid AFP would not have confirmed a fetal NTD, as inadvertent aspiration of the cystic hygroma may give raised amniotic fluid AFP (Sutherland et al, 1977;Sellar, 1977;Cowchock et al, 1982). On ultrasound examination, the presence of trabeculae within the cystic mass may favour a cystic hygroma rather than an encephalocele (Morgan et al, 1975;Cowchock et al, 1982). Cystic hygromas usually occur in Turner's syndrome, monosomy X (Sellar, 1977) but may also occur in Noonan's syndrome (McKusick, 1978), and in trisomy 21 (Stephens and Shepard, 1981).…”