Placental Characteristics of Monoamniotic Twin Pregnancies in Relation to Perinatal Outcome

Managing Monoamniotic Twin Pregnancies

“…The incidence of TTTS in monoamniotic pregnancies is lower than that reported in monochorionic diamniotic pregnancies: 2% to 3% versus 15%. 27 This may be due to the near universal presence of arterioarterial anastomoses in monoamniotic twins, which are thought to be protective against TTTS. 27,28 However, TTTS is still common enough that it is recommended to provide surveillance for TTTS as part of the routine monitoring plan for monoamniotic twin pregnancies.…”

Monochorionic placentas with proximate umbilical cord insertions: Definition, prevalence and angio-architecture

“…Accordingly, the cut-off value for PCI ranged from 3.3 to 4.0 cm across gestation. This cut-off value is slightly lower than the 5 cm cut-off used in previous studies [7,17]. However, the 5 cm cut-off value was based on arbitrary assumptions and not derived from scientific analysis.…”

“…The significant proximity of umbilical cord insertions may be a representative of the later splitting of inner cell mass in MA twin gestations (around 8e12 days after fertilization) compared to MC diamniotic twin gestations (around 4e8 days after fertilization). The short distance between cord insertions in MA placentas is reported to be one of the main causal factors leading to the ubiquitous entanglement of umbilical cords [7,18].…”

Monoamniale Mehrlings-Schwangerschaften

“…Nach M ö glichkeit sollte auch eine spezielle pathologische Untersuchung der Plazenta inklusive der Anastomosen erfolgen. Diese kann man mithilfe von kontrast-angiografi schen Methoden oder mithilfe von farbcodierter Angiogaphie-darstellen [44,77,78] . In einer umfangreichen Untersuchung von Hack et al wurden 55 Zwillingsplazenten untersucht und es konnte festgestellt werden, dass die perinatale Mortalit ä t von MA-Zwillingen nicht mit Gef ä ß anomalien in der Plazenta einherging [77] .…”