Related Experiment Video
Updated: Sep 5, 2025

Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas
Published on: September 5, 2011
Cerebro-placental and umbilico-cerebral ratios in uncomplicated monochorionic twins: Longitudinal references and
Daniela Casati1,2, Alice Zavatta2, Ivan Cortinovis3
1Department of Woman, Mother and Neonate, Buzzi Children's Hospital, ASST Fatebenefratelli Sacco, Milan, Italy.
Objectives:
Monochorionic twins (MC) are at high risk of adverse outcomes and Doppler investigation of umbilical and cerebral flows is mandatory for their surveillance. The cerebro-placental (CPR) and umbilico-cerebral (UCR) ratios are considered non-invasive measures of fetal adaptation to hypoxemia. We aimed to provide longitudinal references for CPR and UCR from 16 to 37 weeks of gestation that are specific for MC twins, and compare these with singleton charts.
Methods:
Longitudinal study of a cohort of consecutive uncomplicated MC twin pregnancies monitored at our unit from 2010 to 2018. The estimated centile curves were obtained estimating the median with fractional polynomials by a multilevel model and the external centiles through the residuals. The comparison with singletons references was made through graphic evaluation.
Results:
One-hundred-fifty-two MC pregnancies were included with a median of 10 longitudinal ultrasounds each. References for CPR and UCR in function of gestational age are presented. Compared to singletons, MC twins showed an earlier and greater circulatory redistribution with lower CPR and higher UCR median values.
Conclusions:
MC twin-specific references for CPR and UCR suitable for serial monitoring are presented. The comparison with singleton references demonstrates substantial differences in the hemodynamic balance that must be considered when interpreting findings in MC twins.
More Related Videos
09:52Accurate and Simple Evaluation of Vascular Anastomoses in Monochorionic Placenta using Colored Dye
Published on: September 5, 2011
09:51Model Surgical Training: Skills Acquisition in Fetoscopic Laser Photocoagulation of Monochorionic Diamniotic Twin Placenta Using Realistic Simulators
Published on: March 21, 2018
Related Concept Videos
Fetal Circulation
Two umbilical arteries transport blood from the fetus to the placenta. At the placenta, the blood absorbs oxygen and nutrients while simultaneously eliminating waste products. This oxygen-enriched and nutrient-rich blood then returns to the fetus through one...
Chi-square Analysis
The chi-square test was developed by Pearson in 1990.
The first step of performing a Chi-square analysis is to establish a null hypothesis, which assumes that there is no real...