title: Functional three-dimensional sonographic study of the postpartum uterus.
abstract: OBJECTIVE
  To demonstrate sequential changes of the postpartum uterus using two- and three-dimensional (2D and 3D) ultrasounds and Doppler studies.
  
  
  METHODS
  Eighty-one women who delivered a singleton at term were recruited for this prospective longitudinal study. Manual and ultrasound examinations of the uterus were performed for seven consecutive weeks. Sequential changes in size of the uterus, endometrial thickness and appearances and Doppler indices of the uterine and arcuate arteries were analyzed.
  
  
  RESULTS
  Complete follow ups were achieved in 71 women who had an uncomplicated postpartum course. 2D and 3D ultrasound estimations of uterine volume are highly correlated with each other (r > 0.7), but not manual estimations (r < 0.3). Data generated from 497 3D observations demonstrated rapid involution of the uterus in the first two weeks after delivery. Breastfeeding and parity did not affect uterine involution (r < 0.2). Resistance index (RI) of the uterine artery started to elevate at four weeks after delivery (r > 0.7). RI of the arcuate artery was not significantly changed during the study period (r < 0.2). Uterine involution was independent from progressive thinning of the endometrium and elevation of uterine artery RI. (r < 0.1 and 0.2, respectively).
  
  
  CONCLUSIONS
  Longitudinal sonographic study showed independent physiologic reversals of uterine volume, endometrium and vascular supply in the first seven weeks following vaginal delivery. Standardization of measurement techniques is essential to apply this information for an early detection of postpartum uterine complications.
authors.affiliation: a Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology , Bangkok , Thailand and.
authors.forename: Tuangsit
authors.initials: T
authors.lastname: Wataganara
authors.affiliation: a Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology , Bangkok , Thailand and.
authors.forename: Nisarat
authors.initials: N
authors.lastname: Phithakwatchara
authors.affiliation: b Division of Clinical Epidemiology, Faculty of Medicine Siriraj Hospital , Mahidol University , Bangkok , Thailand.
authors.forename: Chulaluk
authors.initials: C
authors.lastname: Komoltri
authors.affiliation: a Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology , Bangkok , Thailand and.
authors.forename: Pornpen
authors.initials: P
authors.lastname: Tantisirin
authors.affiliation: b Division of Clinical Epidemiology, Faculty of Medicine Siriraj Hospital , Mahidol University , Bangkok , Thailand.
authors.forename: Julaporn
authors.initials: J
authors.lastname: Pooliam
authors.affiliation: a Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology , Bangkok , Thailand and.
authors.forename: Vitaya
authors.initials: V
authors.lastname: Titapant
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008137:Longitudinal Studies; D049590:Postpartum Period / Q000502:physiology*; D011247:Pregnancy; D011446:Prospective Studies; D018608:Ultrasonography, Doppler / Q000379:methods*; D014599:Uterus / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000502:physiology; D055815:Young Adult
keywords: Physiology; postpartum; three-dimensional sonography; uterine artery Doppler; uterine involution