title: Fetal sonographic characteristics associated with shoulder dystocia in pregnancies of women with type 1 diabetes.
abstract: BACKGROUND
  Shoulder dystocia is a rare but severe complication of vaginal delivery and diabetic women are at high risk. The aim of this study was to identify fetal sonographic and maternal glycemic characteristics associated with shoulder dystocia in pregnant women with type 1 diabetes.
  
  
  METHODS
  Twelve cases (5%) of shoulder dystocia among 241 consecutive vaginal deliveries in women with type 1 diabetes followed at Rigshospitalet University Hospital in 2009-2013 were retrospectively identified in a local database. Fetal sonographic and clinical data were compared with 69 women with type 1 diabetes and uncomplicated vaginal deliveries.
  
  
  RESULTS
  Women experiencing shoulder dystocia compared with women with uncomplicated deliveries had a higher glycated hemoglobin (HbA1c) in early pregnancy [median 7.0% (range 5.9-8.1) vs. 6.6% (range 5.4-10.0, P = 0.04)], whereas in late pregnancy, HbA1c in the two groups of women was comparable [6.1% (range 5.5-6.9) vs. 6.0% (range 4.7-8.4, P = 0.30)]. Fetal biometry at 36 weeks showed a higher estimated fetal weight of 3597 g (range 3051-4069) vs. 2989 g (range 2165-4025), P < 0.001, corresponding to 20% (4-41%) vs. 5% (-20 to 44%) above the mean estimated fetal weight for gestational age (P = 0.002) and a greater abdominal circumference SD score of 2.51 (range 1.56-4.20) vs. 1.33 (range -1.08 to 4.25), P = 0.001). Head circumference was comparable. Vacuum extraction was more frequent during deliveries with shoulder dystocia (58 vs. 17%, P = 0.005). Seven (58%) newborns with shoulder dystocia had brachial plexus injuries, fractures, intra-abdominal bleeding or needed resuscitation.
  
  
  CONCLUSIONS
  Excessive estimated fetal weight and abdominal circumference at 36 weeks' sonographic examination may help in identifying diabetic women at high risk of later shoulder dystocia.
authors.affiliation: Center for Pregnant Women with Diabetes, Rigshospitalet University Hospital, Copenhagen, Denmark.|Department of Endocrinology, Rigshospitalet University Hospital, Copenhagen, Denmark.
authors.forename: Anna L
authors.initials: AL
authors.lastname: Secher
authors.affiliation: Center for Pregnant Women with Diabetes, Rigshospitalet University Hospital, Copenhagen, Denmark.|Department of Obstetrics, Rigshospitalet University Hospital, Copenhagen, Denmark.
authors.forename: Birgitte
authors.initials: B
authors.lastname: Bytoft
authors.affiliation: Department of Obstetrics, Rigshospitalet University Hospital, Copenhagen, Denmark.|Center of Fetal Medicine and Pregnancy, Rigshospitalet University Hospital, Copenhagen, Denmark.|Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Ann
authors.initials: A
authors.lastname: Tabor
authors.affiliation: Center for Pregnant Women with Diabetes, Rigshospitalet University Hospital, Copenhagen, Denmark.|Department of Obstetrics, Rigshospitalet University Hospital, Copenhagen, Denmark.|Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Damm
authors.affiliation: Center for Pregnant Women with Diabetes, Rigshospitalet University Hospital, Copenhagen, Denmark.|Department of Endocrinology, Rigshospitalet University Hospital, Copenhagen, Denmark.|Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Elisabeth R
authors.initials: ER
authors.lastname: Mathiesen
mesh_terms: D000328:Adult; D001720:Birth Injuries / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D015992:Body Mass Index; D001917:Brachial Plexus / Q000293:injuries; D003922:Diabetes Mellitus, Type 1; D005260:Female; D020567:Fetal Weight; D006442:Glycated Hemoglobin; D006801:Humans; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011254:Pregnancy in Diabetics / Q000000981:diagnostic imaging*; D012307:Risk Factors; D016216:Ultrasonography, Prenatal; D014620:Vacuum Extraction, Obstetrical / Q000009:adverse effects; D055815:Young Adult
chemical_list: D006442:Glycated Hemoglobin
keywords: diabetes; fetal disproportion; fetal weight; shoulder dystocia; vaginal delivery