Related Experiment Video
Updated: Apr 7, 2026
09:04
Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas
Published on: September 5, 2011
15.5K
Twin reversed arterial perfusion sequence is more common than generally accepted
Martin J C van Gemert1, Jeroen P H M van den Wijngaard1,2, Frank P H A Vandenbussche3
1Department of Biomedical Engineering & Physics, Academic Medical Center, Amsterdam, The Netherlands.
Summary
Acardiac twinning, a complication of monochorionic twin pregnancies, is more common than previously thought. Updated analysis reveals an incidence of 2.6%, challenging older estimates and highlighting the need for further research into embryonic development.
Area of Science:
- Reproductive Medicine
- Developmental Biology
- Obstetrics
Background:
- Monochorionic twin pregnancies often share a placenta with vascular connections (anastomoses).
- These placental anastomoses can lead to serious complications like acardiac twinning, where one twin lacks a heart but develops due to perfusion from the other.
- Previous estimates of acardiac twinning incidence are outdated.
Purpose of the Study:
- To update the incidence of acardiac twinning in monochorionic pregnancies.
- To assess acardiac twinning rates considering early developmental cessation and assisted reproductive technologies (ART).
- To evaluate acardiac twinning in the context of arterioarterial (AA) and venovenous (VV) placental anastomoses.
Main Methods:
- Utilized the established 1.1% incidence of monochorionic acardiac twinning.
- Incorporated a 58% rate of early acardiac development cessation.
- Accounted for the impact of assisted reproductive technologies (ART) on twinning rates.
- Assessed incidence under conditions of AA-VV anastomoses.
Main Results:
- The incidence of early acardiac monochorionic twinning is estimated at 2.6% (1 in 9,500 to 11,000 pregnancies).
- This represents a significant increase from the historical 1% incidence (1 in 35,000 pregnancies).
- Acardiac twinning occurs in approximately 1 in 8 monochorionic placentas with AA-VV anastomoses.
Conclusions:
- Early acardiac twinning is not a rare event.
- The historical 1% incidence is based on weak evidence and likely underestimates the true rate.
- More precise incidence data can enhance understanding of embryonic splitting in unequal cell masses.
