Color-dye injection of monochorionic placentas and correlation with pregnancy complications.
BACKGROUND
Vascular anastomoses in monochorionic (MC) twin placenta can be easily identified with color-dye injection. The aim of this study is to analyze the relationship between different type of anastomoses and twin pregnancy complications.


METHODS
From January 2011 to October 2014, MC placentas were analyzed with color-dye injection and five group of pregnancies were identified: those that were not complicated (NC), those complicated with selective intrauterine growth restriction (sIUGR), twin-twin transfusion syndrome (TTTS), or twin anemia-polycitemia sequence (TAPS) and those with amniotic fluid discordance (AFD) between twins. Cases of TTTS treated with endoscopic laser coagulation of placenta anastomoses or cases with in utero death of one twin were excluded.


RESULTS
A total of 118 MC placentas were observed, 58 (49%) NC, 35 (30%) sIUGR, 10 (8%) TTTS, 13 (11%) AFD and 2 (2%) TAPS. The median number of anastomoses was 7 (range 1-15), 8 (2-18), 4 (2-11), 7 (2-13) and 1 (1-1), respectively. At least one artero-venous anastomoses was found in the placenta observed, while the prevalence of artero-arterial anastomoses was 95% for NC, 91% for sIUGR, 60% for TTTS, and 77% for AFD; no TAPS placenta had this type of anastomoses. The diameter of arteroarterial anastomoses was greater in the AFD group (3.3 mm), compared to the NC, sIUGR and TTTS groups (2.3, 2.5 and 1.4 respectively, p 0.04).


CONCLUSIONS
In this large serie of MC placenta analyzed with color-dye injection, a specific distribution of anastomoses emerged for twins with amniotic fluid discordance, which points to a need for intensive surveillance.
Department of Obstetrics and Gynecology, Children's Hospital V. Buzzi, Milan, Italy. Electronic address: marianomatteo.lanna@fastwebnet.it.
Mariano Matteo
MM
Lanna
Unit of Epidemiology Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Italy.
Dario
D
Consonni
Department of Obstetrics and Gynecology, Children's Hospital V. Buzzi, Milan, Italy.
Stefano
S
Faiola
Department of Obstetrics and Gynecology, Children's Hospital V. Buzzi, Milan, Italy.
Vito
V
Schena
Department of Obstetrics and Gynecology, Children's Hospital V. Buzzi, Milan, Italy.
Martina
M
Ratti
Department of Obstetrics and Gynecology, Children's Hospital V. Buzzi, Milan, Italy.
Enrico
E
Ferrazzi
Department of Obstetrics and Gynecology, Children's Hospital V. Buzzi, Milan, Italy.
Maria Angela
MA
Rustico
D000328:Adult; D016022:Case-Control Studies; D004396:Coloring Agents; D005260:Female; D005317:Fetal Growth Retardation / Q000473:pathology*; D005330:Fetofetal Transfusion / Q000473:pathology*; D006801:Humans; D007267:Injections; D008875:Middle Aged; D010920:Placenta / Q000473:pathology*; D011247:Pregnancy; D014430:Twins, Monozygotic; D055815:Young Adult
D004396:Coloring Agents
Amniotic fluid discordance; Monochorionic placenta; Placenta anastomoses; TAPS; TTTS; sIUGR