Journal of Clinical Neonatology

CASE REPORT
Year
: 2022  |  Volume : 11  |  Issue : 3  |  Page : 192--194

Difference in the nucleated red blood cell counts among donor and receipt twins affected by Twin‒Twin transfusion syndrome


Shabih Manzar 
 Department of Pediatrics, Division of Neonatology, School of Medicine, Louisiana State University Health Sciences Center, Shreveport, LA, USA

Correspondence Address:
Shabih Manzar
1501 Kings Highway, Shreveport, LA 71103
USA

Abstract

A high nucleated red blood cell (NRBC) count at birth is taken as a biomarker of fetal hypoxia. In twin-to-twin transfusion syndrome (TTTS), the communication of placental vessels between the donor and recipient twin creates an imbalance of blood flow resulting in anemia in the donor and polycythemia in the recipient. The anemia in donors results in hypoxia. The NRBC count could be used as a biomarker of chronic hypoxia in donor twins. A literature search shows no previous report on the NRBC count at birth comparing donor and recipient twins in TTTS. We present a case of TTTS with a discussion on the pathophysiology of elevated NRBC at birth in donor twins.



How to cite this article:
Manzar S. Difference in the nucleated red blood cell counts among donor and receipt twins affected by Twin‒Twin transfusion syndrome.J Clin Neonatol 2022;11:192-194


How to cite this URL:
Manzar S. Difference in the nucleated red blood cell counts among donor and receipt twins affected by Twin‒Twin transfusion syndrome. J Clin Neonatol [serial online] 2022 [cited 2022 Dec 9 ];11:192-194
Available from: https://www.jcnonweb.com/text.asp?2022/11/3/192/350034


Full Text



 Introduction



A high nucleated red blood cell (NRBC) count at birth is taken as a biomarker of fetal hypoxia.[1],[2] Mori et al.[3] studied 98 twins and found a significant intertwin difference in the Log10 (NRBC/100 white blood cell [WBC]), concluding that the smaller twins experienced a relative lack of oxygen compared with the larger twin in utero. Twin-to-twin transfusion syndrome (TTTS) affects about 10%–15% of monochorionic multiple pregnancies. The communication of placental vessels between the donor and recipient twin creates an imbalance of blood flow resulting in anemia in the donor and polycythemia in the recipient.[4] TTTS is being monitored by the antenatal ultrasound, staged, and treated according, however, complications still occur.[5] The chronic hypoxia in donor twins is concerning. As stated earlier, in these cases, NRBC could be used as a biomarker. A literature search did not result in any earlier report on the NRBC count at birth comparing donor and recipient twins in TTTS.

 Case Report



The twins (donor and recipient) were delivered at 322/7 weeks of gestation. The pregnancy was complicated by monochorionic diamniotic twinning with TTTS. Laser ablation was done after 27 weeks of gestation. The birth measurements and red cell indices and NRBC/100 WBC are shown in [Table 1]. It is interesting to note a difference of 97% difference in NRBC between the donor and recipient, whereas other parameters are <20% difference.{Table 1}

 Discussion



In humans, during embryonic and fetal development, the liver is a major hematopoietic organ. Hematopoiesis occurs in four distinct stages, stage I consist of the onset of liver hematopoiesis, stages II and III, expansion of the volume of hematopoietic component, and stage IV involution of liver hematopoiesis.[6],[7] Any distress during fetal development stimulates hepatic erythropoiesis which results in a high number of NRBC in the circulation. This stress-induced erythropoiesis in utero has been shown in fetuses affected by congenital heart diseases.[8] The clinical relevance of NRBC has been described earlier. Elevated NRBC counts are a predictor of mortality in preterm infants.[9] It is therefore essential to follow the NRBC counts in preterm infants.

The pathophysiology of elevated NRBC in the donor is explained in [Figure 1]. Through arteriovenous anastomosis, the blood flows from the donor to the recipient. If laser ablation is delayed, the continuous process of blood flowing unidirectionally makes the donor anemic. The decrease in red cells predisposes the fetus to hypoxia, which elevates erythropoietin (EPO) levels.[10],[11],[12] The elevated EPO then stimulates the hemopoiesis in the fetal hemopoietic organs producing an increased NRBC. [Figure 2] shows the difference in the levels of NRBC between donor and recipient. [Figure 3] demonstrates the comparison with normal ranges of NRBC.[13]{Figure 1}{Figure 2}{Figure 3}

Both twins are currently being cared in the neonatal intensive care unit. They are 18-day-old at the time of this report. The NRBC has normalized in both.

In conclusion, NRBC count at birth indicates chronic hypoxia in the donor twin in the cases of TTTS. Further studies are needed to correlate the magnitude of NRBC counts at birth with the outcome of TTTS.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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