by Borrell, A. et al.
Prenatal Diagnosis Unit, Institute of Gynecology, Obstetrics and Neonatology, Hospital Clinic, Spain
Prenatal Diagnosis Unit, Institute of Gynecology, Obstetrics and Neonatology, Hospital Clinic, Spain
Combining fetal nuchal fold thickness with second-trimester biochemistry to screen for trisomy 21.
Ultrasound. Obstet. Gynecol. 2007; 7:941-5