title: Yolk sac diameter in early pregnancy in maternal diabetes mellitus.
abstract: OBJECTIVE
  To investigate the possible association between maternal diabetes mellitus and increased yolk sac diameter (YSD).
  
  
  METHODS
  We searched the Early Pregnancy Unit database to identify singleton pregnancies with measurements of embryonic crown-rump length (CRL) and YSD at 6-10 weeks of gestation and subsequent delivery of phenotypically normal neonates. We compared the YSD in patients with pre-gestational and gestational diabetes with those who were unaffected by diabetes.
  
  
  RESULTS
  A total of 3,686 cases were identified including 43 (1.2%) with type 1 diabetes, 31 (0.8%) with type 2 diabetes and 71 (1.9%) who subsequently developed gestational diabetes. The measured YSD in both the diabetic and non-diabetic groups were expressed as differences from the expected normal mean for CRL (Δ values). There were no significant differences in ΔYSD between the groups. The median (IQR) ΔYSD was 0.01 (-0.33 to 0.37) mm in the unaffected group, 0.01 (-0.35 to 0.51) mm in type 1 diabetes, -0.02 (-3.44 to 0.27) mm in type 2 diabetes and 0.01 (-0.28 to 0.35) mm in gestational diabetes.
  
  
  CONCLUSIONS
  After exclusion of miscarriages and embryopathies, pre-gestational and gestational diabetes are not associated with altered YSD.
authors.affiliation: Fetal Medicine Unit, King's College Hospital, London, UK.
authors.forename: George I
authors.initials: GI
authors.lastname: Papaioannou
authors.forename: Argyro
authors.initials: A
authors.lastname: Syngelaki
authors.forename: Nerea
authors.initials: N
authors.lastname: Maiz
authors.forename: Jackie A
authors.initials: JA
authors.lastname: Ross
authors.forename: Kypros H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D018568:Crown-Rump Length; D003922:Diabetes Mellitus, Type 1 / Q000000981:diagnostic imaging / Q000473:pathology*; D003924:Diabetes Mellitus, Type 2 / Q000000981:diagnostic imaging / Q000473:pathology*; D016640:Diabetes, Gestational / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal; D015017:Yolk Sac / Q000000981:diagnostic imaging / Q000473:pathology*