Placental types and twin-twin transfusion syndrome

Carlos Bermúdez, Carlos H. Becerra, Patricia W. Bornick, Mary H. Allen, Jorge Arroyo, Rubén A. Quintero

Research output: Contribution to journalArticlepeer-review

84 Scopus citations


OBJECTIVE: The purpose of this study was to assess the value of a proposed classification of monochorionic placenta in reference to twin-twin transfusion syndrome. STUDY DESIGN: The placentas from laser-treated patients with twin-twin transfusion syndrome and from uncomplicated monochorionic pregnancies that were delivered between January 1997 and December 2000 were included in the study. Placentas were classified as type A (no anastomoses), type B (only deep anastomoses), type C (only superficial anastomoses), and type D (deep and superficial anastomoses). The number and type of anastomoses were documented in each placental type. The severity of twin-twin transfusion syndrome was assessed in stages, as previously described. The relationship between placental types and the development and severity of twin-twin transfusion syndrome was determined. RESULTS: One hundred thirty-one placentas were examined. Twin-twin transfusion syndrome developed in 0% (0/4 placentas) of type A, in 100% (85/85 placentas) of type B, in 5.6% (1/18 placentas) of type C, and in 79.17% (19/24 placentas) of type D placentas. An average of 4.17 (range, 1-11) vascular anastomoses was found. The mean number of superficial anastomoses was not different between patients with twin-twin transfusion syndrome and patients with no twin-twin transfusion syndrome (1.6 vs 1.71, respectively; P = .69, Student t test). The presence or absence of superficial anastomoses was not associated with differences in the severity of twin-twin transfusion syndrome. CONCLUSION: This classification represents a practical approach to the surgical pathologic assessment of vascular anastomoses in monochorionic placentas, with a strong clinical correlation. It also allows for the clarification of the relationship between superficial anastomoses and twin-twin transfusion syndrome.

Original languageEnglish (US)
Article number00157
Pages (from-to)489-494
Number of pages6
JournalAmerican journal of obstetrics and gynecology
Issue number2
StatePublished - 2002


  • Fetal therapy
  • Laser photocoagulation
  • Placental anastomoses
  • Twin-twin transfusion syndrome
  • Twins

ASJC Scopus subject areas

  • Medicine(all)
  • Obstetrics and Gynecology


Dive into the research topics of 'Placental types and twin-twin transfusion syndrome'. Together they form a unique fingerprint.

Cite this