September 15th, 2019

A full text version of this article is available.
To access article obtain online access here or login
Ultrasound Measurement of Twin Dividing Membrane Thickness and Risk of Spontaneous Preterm Birth
Authors:  Luis A. Bracero, M.D., Matthew J. Blitz, M.D., M.B.A., Dara J. Seybold, M.A.A., Mike Broce, B.A., Arsal Khan, B.S., and Sarah J. Turner, M.D.
  OBJECTIVE: To determine if prenatal ultrasound measurements of dividing membrane thickness (DMT) can predict spontaneous preterm birth (sPTB) and histologically-confirmed chorionicity in twin pregnancies.

STUDY DESIGN: Prospective cohort in which DMT was measured by transabdominal ultrasound, both parallel and perpendicular to the transducer.

RESULTS: A total of 73 twin pregnancies were included: 54 dichorionic-diamniotic (DCDA) and 19 monochorioniciamniotic (MCDA). Overall, 75.9% of DCDA and 100% of MCDA gestations delivered preterm (p<0.02); these were categorized as spontaneous in 78.0% of DCDA and 84.2% of MCDA gestations. Ultimately, no association between DMT and sPTB was identified. However, DMT was associated with overall PTB at <37 weeks, with receiver operating characteristic curve analyses resulting in an area under the curve (AUC) of 0.756 for parallel (p<0.006) and 0.725 for perpendicular (p<0.016) measurements with cutoff values of 2.6 and 2.7 mm, respectively. The AUC to predict monochorionicity was 0.950 (p<0.001) for parallel measurements and 0.883 (p<0.001) for perpendicular measurements, with cutoff values of 1.9 and 1.8 mm, respectively.

CONCLUSION: Ultrasound-measured DMT is not associated with sPTB in twin pregnancies. DMT <2.6 mm is associated with an increased risk of overall PTB, though the etiology is uncertain. Monochorionicity can be determined by DMT <1.9 mm.
Keywords:  chorionicity, membrane thickness, pre­term birth, twin pregnancy, ultrasound measure­ments
  Acrobat Reader 7.0 is recommended to properly view and print the article.
Reader can be downloaded from