10.1016/0002-9378(94)90036-1
10.1016/S0029-7844(97)00131-2
10.1046/j.1469-0705.1998.11040303.x
10.1016/S0002-9378(12)80029-9
10.1016/0002-9378(95)91334-3
10.1016/S0002-9378(96)80006-8
10.1016/S0002-9378(98)70036-5
10.1016/S0002-9378(99)70170-5
10.1016/S0002-9378(87)80279-X
10.1016/0002-9378(85)90385-0
10.1148/radiology.163.3.2953039
10.1056/NEJM198711263172203
10.1016/0002-9378(88)90517-0
10.1016/0002-9378(88)90165-2
10.1148/radiology.173.2.2529580
Benacerraf BR, 1990, Fetal pyelectasis: a possible association with Down syndrome, Obstet Gynecol, 76, 58
10.1016/0002-9378(90)91304-U
10.1097/00006250-199102000-00012
10.7863/jum.1992.11.9.449
10.1148/radiology.193.1.8090881
Birnholz JC, 1988, Fetal ear length, Pediatrics, 81, 555
10.1016/S0029-7844(97)00089-6
10.1016/S0002-9378(96)70249-1
10.7863/jum.1995.14.3.253
Bromley B, 1994, Is fetal hyperechoic bowel on second‐trimester sonogram an indication for amniocentesis?, Obstet Gynecol, 83, 647
10.1016/0029-7844(95)00323-J
10.1046/j.1469-0705.1996.08040232.x
10.7863/jum.1998.17.2.127
10.7863/jum.1999.18.8.523
10.1016/S0029-7844(99)00457-3
10.7863/jum.1994.13.8.613
Brumfield CG, 1989, Sonographic measurements and ratios in fetuses with Down syndrome, Obstet Gynecol, 73, 644
Corteville JE, 1992, Fetal pyelectasis and Down syndrome: is genetic amniocentesis warranted?, Obstet Gynecol, 79, 770
Crane JP, 1991, Sonographically measured nuchal skinfold thickness as a screening tool for Down syndrome: results of a prospective clinical trial, Obstet Gynecol, 77, 533
Dicke JM, 1992, Sonographically detected hyperechoic fetal bowel: significance and implications for pregnancy management, Obstet Gynecol, 80, 778
Dicke JM, 1989, Fetal biometry as a screening tool for the detection of chromosomally abnormal pregnancies, Obstet Gynecol, 74, 726
Donnenfeld AE, 1994, Prospective multicenter study of second‐trimester nuchal skinfold thickness in unaffected and Down syndrome pregnancies, Obstet Gynecol, 84, 844
10.1016/0029-7844(96)00134-2
Fakhry J, 1985, Increased echogenicity in the lower fetal abdomen: a common normal variant in the second trimester, J Ultrasound Med, 5, 489, 10.7863/jum.1986.5.9.489
10.1016/0002-9378(89)90658-3
10.1002/(SICI)1096-8628(19981116)80:3<213::AID-AJMG6>3.0.CO;2-8
10.1016/0002-9378(90)90686-2
10.1016/0029-7844(94)00327-A
10.1016/0002-9378(95)90162-0
10.1148/radiology.174.3.2137635
10.1016/0002-9378(95)90088-8
10.1016/0002-9378(91)90636-6
10.7863/jum.1993.12.8.451
10.1016/S0029-7844(96)00330-4
Johnson MP, 1995. Combining humerus and femur length for improved ultrasonographic identification of pregnancies at increased risk for trisomy 21, Am J Obstet Gynecol, 172, 1229, 10.1016/0002-9378(95)91484-6
Jones KL, 1997, Smith's Recognizable Patterns of Human Malformation
10.7863/jum.1989.8.12.657
10.1148/radiology.194.1.7997556
Lettieri L, 1993, Ear length in second‐trimester aneuploid fetuses, Obstet Gynecol, 81, 57
10.1016/S0002-9378(87)80059-5
Lynch L, 1989, Ultrasound detection of Down syndrome: is it really possible?, Obstet Gynecol, 73, 267
10.1016/0002-9378(95)91365-3
10.1002/(SICI)1097-0223(199704)17:4<319::AID-PD26>3.0.CO;2-P
10.1002/(SICI)1097-0223(199812)18:12<1253::AID-PD442>3.0.CO;2-B
10.1002/(SICI)1097-0223(199902)19:2<142::AID-PD486>3.0.CO;2-7
10.7863/jum.1995.14.4.297
10.1016/0140-6736(92)92240-G
10.1016/0002-9378(90)90028-6
10.1016/0002-9378(93)90487-4
10.1046/j.1469-0705.1993.03050330.x
10.1148/radiology.188.2.8327709
Nyberg DA, 1993, Prenatal sonographic findings of trisomy 18: review of 47 cases, J Ultrasound Med, 2, 103, 10.7863/jum.1993.12.2.103
10.1016/0002-9378(95)91322-X
10.1046/j.1469-0705.1998.12010008.x
10.1016/0002-9378(89)90502-4
10.1046/j.1469-0705.1995.05020092.x
10.1016/0046-8177(92)90031-W
10.1016/S0029-7844(97)00076-8
10.7863/jum.1987.6.12.691
10.1016/S0002-9378(12)80007-X
10.1046/j.1469-0705.1998.12060445.x
10.1111/j.1471-0528.1995.tb11325.x
10.7863/jum.1998.17.5.327
10.1002/(SICI)1097-0223(199706)17:6<545::AID-PD108>3.0.CO;2-3
10.1016/S0029-7844(97)00508-5
10.1046/j.1469-0705.1998.12010015.x
10.1046/j.1469-0705.2000.00138.x
10.7863/jum.2001.20.2.141
10.1046/j.1469-0705.1996.08040225.x
Snijders RJM, 1996, Ultrasound Markers for Fetal Chromosomal Defects
10.1046/j.1469-0705.1999.13030167.x
10.1046/j.1469-0705.1995.05060384.x
10.1111/j.1471-0528.1998.tb10230.x
10.1016/0002-9378(87)90227-4
10.1111/j.1471-0528.1998.tb09352.x
10.7863/jum.1999.18.4.265
10.1016/0002-9378(95)90008-X
10.1016/0029-7844(96)00058-0
10.1016/0029-7844(96)00053-1
10.1016/S0029-7844(97)00152-X
10.1016/S0029-7844(97)00227-5
10.1016/S0002-9378(94)70232-2
10.7863/jum.1998.17.3.141
10.1016/0029-7844(96)00211-6
10.7863/jum.1994.13.3.229
10.1148/radiology.207.1.9530318
10.1016/S0029-7844(98)00544-4
10.1148/radiology.211.2.r99ma34447
10.1046/j.1469-0705.1998.12010019.x