title: Routine screening for fetal limb abnormalities in the first trimester.
abstract: OBJECTIVE
  We aim to determine the accuracy of first-trimester ultrasonography in detecting fetal limb abnormalities.
  
  
  METHODS
  This is a retrospective study of all women undergoing fetal nuchal translucency (NT) assessment and detailed fetal anatomic survey in the first trimester at a single tertiary-care referral center in China. Fetal anatomy scans were repeated in the second trimester. Detection of fetal limb abnormalities was compared between first and second trimester anatomy scans and confirmed at delivery or at autopsy.
  
  
  RESULTS
  Analyzed were 9438 fetuses from 9197 women (241 twin pairs). The incidence of fetal limb abnormalities was 0.38% (36/9438). Of these, 28 (77.8%) were diagnosed prenatally: 23 (63.9%) on first trimester scan and 5 (13.9%) on second trimester scan. Limb reduction defects (usually transverse limb deficiencies) were the most common limb defects identified in the first trimester (n = 12), followed by clubfoot (n = 4), skeletal dysplasia (n = 3), sirenomelia (n = 1), limb dysplasia (n = 1), malposition (n = 1), and syndactyly (n = 1). Nine fetuses with isolated limb abnormalities had normal NT, while 74.1% (20/27) of limb abnormalities that were associated with other abnormalities had increased NT.
  
  
  CONCLUSIONS
  This study demonstrates that the majority of limb abnormalities detected prenatally [23/28 (82%)] can be identified in the first trimester, especially major limb defects; however, our numbers are small and still need larger cases for further investigation.
authors.affiliation: Department of Ultrasound, Shenzhen Maternity & Child Healthcare Hospital, Southern Medical University, Shenzhen, Guangdong, China.
authors.forename: Yi-Mei
authors.initials: YM
authors.lastname: Liao
authors.affiliation: Department of Ultrasound, Shenzhen Maternity & Child Healthcare Hospital, Southern Medical University, Shenzhen, Guangdong, China.
authors.forename: Sheng-li
authors.initials: SL
authors.lastname: Li
authors.affiliation: Department of Obstetrics & Gynecology, School of Medicine, University of Connecticut, Farmington, CT, USA.
authors.forename: Guo-yang
authors.initials: GY
authors.lastname: Luo
authors.affiliation: Department of Ultrasound, Shenzhen Maternity & Child Healthcare Hospital, Southern Medical University, Shenzhen, Guangdong, China.
authors.forename: Hua-xuan
authors.initials: HX
authors.lastname: Wen
authors.affiliation: Department of Central Laboratory, Shenzhen Maternity & Child Healthcare Hospital, Southern Medical University, Shenzhen, Guangdong, China.
authors.forename: Shu-yuan
authors.initials: SY
authors.lastname: Ouyang
authors.affiliation: Department of Ultrasound, Shenzhen Maternity & Child Healthcare Hospital, Southern Medical University, Shenzhen, Guangdong, China.
authors.forename: Cong-ying
authors.initials: CY
authors.lastname: Chen
authors.affiliation: Department of Ultrasound, Shenzhen Maternity & Child Healthcare Hospital, Southern Medical University, Shenzhen, Guangdong, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Department of Ultrasound, Shenzhen Maternity & Child Healthcare Hospital, Southern Medical University, Shenzhen, Guangdong, China.
authors.forename: Jing-ru
authors.initials: JR
authors.lastname: Bi
authors.affiliation: Department of Ultrasound, Maternity & Child Healthcare Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi, China.
authors.forename: Xiao-xian
authors.initials: XX
authors.lastname: Tian
mesh_terms: D000293:Adolescent; D000328:Adult; D001848:Bone Diseases, Developmental / Q000000981:diagnostic imaging; D002681:China; D003025:Clubfoot / Q000000981:diagnostic imaging; D004480:Ectromelia / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D017880:Limb Deformities, Congenital / Q000000981:diagnostic imaging*; D008875:Middle Aged; D048208:Nuchal Translucency Measurement; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013576:Syndactyly; D062606:Tertiary Care Centers; D016216:Ultrasonography, Prenatal / Q000379:methods*; D055815:Young Adult