Evaluation of Color Difference in Placenta with Twin Anemia Polycythemia Sequence

Summary

In monochorionic twins with twin anemia polycythemia sequence (TAPS), the donor twin and its corresponding placenta share are pale, while the recipient twin and its placental share have a plethoric aspect. Presented here is a protocol to quantify the color difference in maternal side of TAPS placenta after birth.

Abstract

Twin anemia polycythemia sequence (TAPS) occurs in 5% of monochorionic twins and is characterized by large inter-twin hemoglobin differences. The postnatal diagnostic criteria for TAPS are based on hematologic parameters and placental characteristics. Placental examination after birth shows that color of the maternal side between placental territories of the anemic and polycythemic twins is remarkably different. The color difference in TAPS placentas is higher compared to monochorionic placentas with acute peripartum feto-fetal transfusion; thus, this is used as an additional diagnostic criterion for TAPS. Software such as ImageJ enables the computer-based measurement of color intensity in TAPS placentas. However, a detailed method for the calculation of color differences between anemic and polycythemic components of TAPS placentas has not yet been described. The protocol presented here provides a step-by-step method for analyzing color differences in the maternal side of TAPS placentas using ImageJ software.

Introduction

TAPS is a chronic form of feto-fetal transfusion syndrome and characterized by a large inter-twin hemoglobin (Hb) difference without signs of oligo-polyhydramnios sequences¹. The main pathogenesis of TAPS is related to the unique placental angioarchitecture, with only a few minuscule anastomoses allowing for chronic and low velocity transfusion from the donor (anemic twin) to recipient (polycythemic twin)^2,3,4. Postnatal diagnosis of TAPS is based on hematological tests showing a large Hb difference and large reticulocyte count difference and/or placen....

Protocol

This protocol was approved by the Leiden University Medical Center Ethics committee, and postnatal examination of human monochorionic twin placentas is a part of standard care at the Leiden University Medical Center. The acquisition of consent for postnatal examination of human monochorionic twin placentas is waived at the Leiden University Medical Center.

1. TAPS placenta collection and gross examination

1. Use all human monochorionic twin placentas with TAPS delivered at any gestational age. Keep the human monochorionic twin placenta as intact as possible. Deliver the monochorionic placenta as gently as possible, if manual remova....

Results

Placental examination provides valuable information for the diagnosis of TAPS. TAPS placentas are characterized by the presence of few small vascular anastomoses¹ (Figure 1, Figure 2). This feature of TAPS placentas is related to the pathogenesis of TAPS and is a postnatal diagnostic criterion. Similar to the color of neonates at birth, the placenta share of the recipient twin in TAPS is typically dark and plethoric, and the placenta shar.......

Discussion

Key points to achieving an optimal examination based on our experience include: 1) delivery of the placenta as gently as possible to avoid damage, especially when manual removal is indicated; 2) examination of MC placentas soon after birth to avoid the formation of adhesive clots (preferably within a few days); 3) gentle removal of all blood clots, avoiding damage to the placental lobes; 4) exposure of the maternal side of MC placentas to uniform light conditions and minimization of the light reflection; and 5) taking pi.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
20 ml syringes	BD Plastipak	300613
Color dye	Royal Talens Schoolverf	36716010 (blue); 36715010 (green); 36712350 (yellow); 36713570 (pink)
Digital camera	Canon Inc.	ixus 125 hs
ImageJ	National Institute of Health	For Windows ImageJ bundled with 64-bit Java 1.8.0_112
Umbilical catheters	Vygon	1270.08 (8 F) 1270.08 (5 F) 1270.04 (4 F) 1270.03 (3.5 F) 1270.02 (2.5 F)