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 placental injection with dye showing only minuscule anastomoses5. However, reticulocyte count is not always measured at birth, and placental injection is not routinely performed in most fetal medicine centers. An additional diagnostic criterion may be useful to help diagnose cases without reticulocyte count measurements and without placental dye injection. A striking color difference between the pale skin of a donor twin and the plethoric skin of the recipient twin is consistently present in TAPS twins at birth. A similar color difference of the maternal side between placental territories of the anemic and polycythemic twins is also detected upon gross examination.
It has been recently hypothesized that this placental color difference may be used as a simple and accurate method to confirm a TAPS diagnosis after birth6. The quantification of color difference in TAPS placentas is timesaving compared to placental injection. Additionally, quantification of color difference in TAPS placentas is more cost-effective compared to reticulocyte count. The materials used in this method are easily available in clinical settings Therefore, this method provides simple and accurate criteria for the diagnosis of TAPS. The protocol describes a detailed method for the quantification of color differences from the maternal side of monochorionic placentas with TAPS.
Protocol
Representative Results
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…
Declarações
The authors have nothing to disclose.
Acknowledgements
This study was funded by the National Natural Science Foundation of China (Grant number: 81801465), the Sanming Project of Medicine in Shenzhen (Grant number: SZSM201512012) and National Key Research and Development Program of China (Grant number: 2018YFC1002900).
Materials
| 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) |
Referências
- Lopriore, E., et al. Twin anemia-polycythemia sequence in two monochorionic twin pairs without oligo-polyhydramnios sequence. Placenta. 28 (1), 47-51 (2007).
- Zhao, D., et al. Placental share and hemoglobin level in relation to birth weight in twin anemia-polycythemia sequence. Placenta. 35 (12), 1070-1074 (2014).
- Lopriore, E., et al. Assessment of feto-fetal transfusion flow through placental arterio-venous anastomoses in a unique case of twin-to-twin transfusion syndrome. Placenta. 28 (2-3), 209-211 (2007).
- Lopriore, E., et al. Quantification of feto-fetal transfusion rate through a single placental arterio-venous anastomosis in a monochorionic twin pregnancy. Placenta. 30 (3), 223-225 (2009).
- Tollenaar, L. S. A., et al. Improved prediction of twin anemia-polycythemia sequence by delta middle cerebral artery peak systolic velocity: new antenatal classification system. Ultrasound in Obstetrics and Gynecology. 53 (6), 788-793 (2019).
- Tollenaar, L. S., et al. Color Difference in Placentas with Twin Anemia-Polycythemia Sequence: An Additional Diagnostic Criterion. Fetal Diagnosis and Therapy. 40 (2), 123-127 (2016).
- Zhao, D. P., et al. Prevalence, size, number and localization of vascular anastomoses in monochorionic placentas. Placenta. 34 (7), 589-593 (2013).
- De Paepe, M. E., Burke, S., Luks, F. I., Pinar, H., Singer, D. B. Demonstration of placental vascular anatomy in monochorionic twin gestations. Pediatric and Developmental Pathology. 5 (1), 37-44 (2002).
- Lewi, L., et al. Placental sharing, birthweight discordance, and vascular anastomoses in monochorionic diamniotic twin placentas. American Journal of Obstetrics and Gynecology. 197 (6), 581-588 (2007).
- Robertson, E. G., Neer, K. J. Placental injection studies in twin gestation. American Journal of Obstetrics and Gynecology. 147 (2), 170-174 (1983).
- Lewi, L., et al. The outcome of monochorionic diamniotic twin gestations in the era of invasive fetal therapy: a prospective cohort study. American Journal of Obstetrics and Gynecology. 199 (5), (2008).
- Slaghekke, F., et al. Fetoscopic laser coagulation of the vascular equator versus selective coagulation for twin-to-twin transfusion syndrome: an open-label randomised controlled trial. Lancet. 383 (9935), 2144-2151 (2014).
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