“…Beginning in the late 1980s, numerous reports review the prenatal ®ndings associated with trisomy 18 (Warner and Roth, 1986;Benacerraf, 1989;Dicke and Crane, 1991;Nicolaides et al, 1992a,b;Nyberg et al, 1993;Kurjak et al, 1999). Some of these ®ndings include: intrauterine growth retardation (IUGR) (Salihu et al, 1997;Nyberg et al, 1993;Twining et al, 1993); abnormal growth, as measured by the biparietal diameter and femur length ratio (Benattar et al, 1999); Seoud et al, 1994;Dicke and Crane, 1991;(Ginsberg et al, 1990); choroid plexus cysts (Reinsch, 1997;Donnenfeld, 1995;Nadel et al, 1992;Platt et al, 1991;Fitzsimmons et al, 1989;Ostlere et al, 1989;Chitkara et al, 1988); abnormal positioning of ®ngers and clenched hand (Quintero et al, 1999); cardiac abnormalities (Gembruch et al, 1997;Paladini et al, 1993;Wladimiroff et al, 1989); echogenic bowel (Sipes et al, 1994;Scioscia et al, 1992); and facial and head abnormalities (Nicolaides et al, 1992a(Nicolaides et al, ,b,1993Benacerraf et al, 1986). Other unusual ®ndings with more uncertain implications include cystic hygroma (Shields et al, 1998); nuchal thickening (Nyberg et al, 1993); single umbilical artery (Sener et al, 1997); and polyhydramnios (Sickler et al, 1997).…”