title: Do Doppler studies enhance surveillance of uncomplicated monochorionic diamniotic twins?
abstract: OBJECTIVE
  To determine whether isolated abnormal Doppler indices before 28 weeks predict adverse pregnancy outcomes in uncomplicated monochorionic diamniotic (MCDA) twins.
  
  
  METHODS
  A retrospective cohort study of MCDA twin pregnancies receiving antenatal testing at a single center between 2007 and 2013 was conducted. Sonographic surveillance, including Doppler velocimetric studies of the umbilical artery, ductus venosus, and middle cerebral artery of each twin, was initiated by 28 weeks and repeated at least every 2 weeks. All pregnancies were deemed "uncomplicated" at initial sonography, without evidence of polyhydramnios, oligohydramnios, intrauterine growth restriction, twin growth discordance of at least 20%, structural or chromosomal anomalies, or unclear chorionicity. Pregnancies were divided into 2 groups: those with isolated Doppler abnormalities before 28 weeks and those with normal Doppler indices. The primary outcome was a composite including twin-twin transfusion syndrome, intrauterine growth restriction of more than 1 twin, growth discordance of at least 20%, preterm delivery before 34 weeks for fetal indications, or demise of more than 1 fetus.
  
  
  RESULTS
  Ninety-six patients were included, with 22 (22.9%) having isolated Doppler abnormalities before 28 weeks. The incidence of the primary outcome did not differ between groups (36.4% versus 28.4%; P = .47). The abnormal Doppler group underwent a greater number of sonographic examinations (15 versus 10; P= .001) and more antenatal admissions for fetal concerns (50.0% versus 12.2%; P < .001).
  
  
  CONCLUSIONS
  Isolated Doppler abnormalities are commonly encountered in uncomplicated MCDA pregnancies before 28 weeks yet are not clearly predictive of twin-specific complications. Doppler abnormalities were associated with increased sonographic surveillance and antenatal hospitalizations, suggesting an influence on physician practice patterns. Data may not support Doppler studies before 28 weeks for routine MCDA twin monitoring.
authors: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York USA (C.P., S.G.B., N.Z., L.L.S., C.G.-B., R.M.); Department of Obstetrics and Gynecology, Christiana Care Health System, Wilmington, Delaware USA (A.M.); Columbia University College of Physicians and Surgeons, New York, New York USA (K.V.); and Department of Biostatistics, Joseph L. Mailman School of Public Health, Columbia University, New York, New York USA (Y.Z.).
authors: Cara
authors: C
authors: Pessel
authors: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York USA (C.P., S.G.B., N.Z., L.L.S., C.G.-B., R.M.); Department of Obstetrics and Gynecology, Christiana Care Health System, Wilmington, Delaware USA (A.M.); Columbia University College of Physicians and Surgeons, New York, New York USA (K.V.); and Department of Biostatistics, Joseph L. Mailman School of Public Health, Columbia University, New York, New York USA (Y.Z.).
authors: Audrey
authors: A
authors: Merriam
authors: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York USA (C.P., S.G.B., N.Z., L.L.S., C.G.-B., R.M.); Department of Obstetrics and Gynecology, Christiana Care Health System, Wilmington, Delaware USA (A.M.); Columbia University College of Physicians and Surgeons, New York, New York USA (K.V.); and Department of Biostatistics, Joseph L. Mailman School of Public Health, Columbia University, New York, New York USA (Y.Z.).
authors: Kavita
authors: K
authors: Vani
authors: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York USA (C.P., S.G.B., N.Z., L.L.S., C.G.-B., R.M.); Department of Obstetrics and Gynecology, Christiana Care Health System, Wilmington, Delaware USA (A.M.); Columbia University College of Physicians and Surgeons, New York, New York USA (K.V.); and Department of Biostatistics, Joseph L. Mailman School of Public Health, Columbia University, New York, New York USA (Y.Z.).
authors: Sara G
authors: SG
authors: Brubaker
authors: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York USA (C.P., S.G.B., N.Z., L.L.S., C.G.-B., R.M.); Department of Obstetrics and Gynecology, Christiana Care Health System, Wilmington, Delaware USA (A.M.); Columbia University College of Physicians and Surgeons, New York, New York USA (K.V.); and Department of Biostatistics, Joseph L. Mailman School of Public Health, Columbia University, New York, New York USA (Y.Z.).
authors: Noelia
authors: N
authors: Zork
authors: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York USA (C.P., S.G.B., N.Z., L.L.S., C.G.-B., R.M.); Department of Obstetrics and Gynecology, Christiana Care Health System, Wilmington, Delaware USA (A.M.); Columbia University College of Physicians and Surgeons, New York, New York USA (K.V.); and Department of Biostatistics, Joseph L. Mailman School of Public Health, Columbia University, New York, New York USA (Y.Z.).
authors: Yuan
authors: Y
authors: Zhang
authors: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York USA (C.P., S.G.B., N.Z., L.L.S., C.G.-B., R.M.); Department of Obstetrics and Gynecology, Christiana Care Health System, Wilmington, Delaware USA (A.M.); Columbia University College of Physicians and Surgeons, New York, New York USA (K.V.); and Department of Biostatistics, Joseph L. Mailman School of Public Health, Columbia University, New York, New York USA (Y.Z.).
authors: Lynn L
authors: LL
authors: Simpson
authors: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York USA (C.P., S.G.B., N.Z., L.L.S., C.G.-B., R.M.); Department of Obstetrics and Gynecology, Christiana Care Health System, Wilmington, Delaware USA (A.M.); Columbia University College of Physicians and Surgeons, New York, New York USA (K.V.); and Department of Biostatistics, Joseph L. Mailman School of Public Health, Columbia University, New York, New York USA (Y.Z.).
authors: Cynthia
authors: C
authors: Gyamfi-Bannerman
authors: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York USA (C.P., S.G.B., N.Z., L.L.S., C.G.-B., R.M.); Department of Obstetrics and Gynecology, Christiana Care Health System, Wilmington, Delaware USA (A.M.); Columbia University College of Physicians and Surgeons, New York, New York USA (K.V.); and Department of Biostatistics, Joseph L. Mailman School of Public Health, Columbia University, New York, New York USA (Y.Z.).
authors: Russell
authors: R
authors: Miller
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004200:Diseases in Twins / Q000000981:diagnostic imaging*; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging*; D005317:Fetal Growth Retardation; D006801:Humans; D011159:Population Surveillance; D011247:Pregnancy; D012189:Retrospective Studies; D014430:Twins, Monozygotic; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal / Q000379:methods
keywords: Doppler studies; antenatal testing; monochorionic diamniotic; obstetric ultrasound; twins