1. Practice bulletin No 163: screening for fetal aneuploidy;ACOG;Obstet Gynecol,2016
2. Nuchal translucency measurements for first-trimester screening: the ‘price’ of inaccuracy;Evans;Fetal Diagn Ther,2007
3. ISUOG practice guidelines: performance of first-trimester fetal ultrasound scan;ISUOG;Ultrasound Obstet Gynecol,2013
4. Practice bulletin No. 162 prenatal diagnostic testing for genetic disorders;ACOG;Obstet Gynecol,2016
5. Committee opinion No. 640: cell-free DNA screening for fetal aneuploidy;ACOG;Obstet Gynecol,2015