<prompt> Increased nuchal translucency in 13th week fetal ultrasound characteristic of ?Turner syndromeDowns syndromeHydrocephalusKlinefelter syndrome  <response>: Downs syndrome is the most common cause of increased nuchal translucency in fetal ultrasound. The other causes are Trisomy 13, Trisomy 18, Klinefelter syndrome Turners syndrome Ref : Dutta book of obstetrics 8th Ed 