Fetal Brain Injury in Survivors of Twin Pregnancies Complicated by Demise of One Twin: A Review

Abstract

Perinatal mortality is increased considerably in multiple pregnancies compared to singleton pregnancies, with single intrauterine fetal demise (sIUFD) presenting a rare but unique perinatal problem. Monochorionic pregnancies are at particular risk of sIUFD due to bidirectional inter-twin placental vascular anastomoses. The resulting inter-twin blood flow can become unbalanced, causing acute and chronic inter-twin transfusion and profound anemia secondary to fetal exsanguination into the low-pressure circulation of the dead fetus. If the sIUFD occurs after 14 weeks' gestation it is believed to have the most significant effect on the continuing pregnancy as the co-twin is at increased risk of preterm delivery, long-term neurological complications, and death. This article will focus on fetal brain injury in the surviving co-twin in the case of sIUFD, as it is the most common kind of injury in sIUFD, and one which concerns parents and may be the basis for terminating the pregnancy. We will outline how these brain injuries are thought to occur and describe potential pathophysiological mechanisms. We will discuss risk factors for brain injury in cases of sIUFD, including: chorionicity, cause of the sIUFD (spontaneous or secondary to an underlying pathological process such as twin-to-twin transfusion syndrome), gestation of delivery and how to prevent brain injury in the co-twin. We also review modes of imaging, discuss the difficulties in predicting the long-term outcome for co-twin survivors, and highlight the dearth of research in this area.

Neurodevelopmental outcome of monochorionic twins with selective intrauterine growth restriction (SIUGR) type II: laser versus expectant management

“…Expectant management of patients with SIUGR may be associated with an increased risk of adverse perinatal outcome, including prematurity and its attendant complications [8]. Increased risk for spontaneous demise of the SIUGR twin may result in the concomitant demise of the AGA twin in up to 40% of cases or in neurologic damage of the AGA twin in up to 30% of cases [9][10][11][12][13][14][15][16][17][18][19][20][21]. The adverse effects on the AGA twin resulting from the spontaneous demise of the SIUGR twin stem from postmortem fetofetal hemorrhage from the AGA twin to the demised SIUGR twin through placental vascular communications [15,22].…”

Current status of percutaneous umbilical cord blood sampling in Japan

“…The prognosis of the co‐twin depends on the severity of anemia . When this event occurs after 14 weeks gestation, it may have a significant effect on co‐twins . In order to evaluate the severity of anemia in the surviving co‐twin or pump twin, PUBS was performed in 34 cases of monochorionic twin pregnancies in the current study.…”

A Modified Technique for Cord Transection in Monochorionic Monoamniotic Twin Pregnancies

“…In contrast, abundant data exists on monochorionic diamniotic twin gestations after sIUD. Exaggerated mortality but also morbidity have been observed in monochorionic twins following sIUD, the most severe being brain injuries in approximately 1 out of 4 cases [17][18][19][20]. Brain damage in the surviving twin can occur as early as 30 min post mortem of the co-twin and has been reported to be present in postnatal cranial imaging in approximately 34% of monochorionic single survivors [21,22].…”