Imaging diagnosis and legal implications of brain injury in survivors following single intrauterine fetal demise from monochorionic twins – a review of the literature

Abstract

Brain injury of the surviving twin from monochorionic pregnancies following intrauterine fetal demise during the second and third trimesters is a rare but severe complication. Monochorionicity and gestational age at the time of stillbirth seem to be decisive factors in terms of long-term neurologic outcome prediction for the survivor. Magnetic resonance imaging (MRI), diffusion weighted imaging (DWI) in particular, seem to bring the earliest and most accurate diagnosis. Ultrasound detection of brain damage is possible in later stages of fetal brain injury. It is essential to provide early diagnosis and multidisciplinary counsel to the parents to ensure informed decision making. For couples who choose to terminate pregnancy legislation related to late abortion might lead to further distress. Our paper aims to stress the importance of MRI DWI in the evaluation of surviving twins following single intrauterine fetal demise in monochorionic pregnancies and the delicate context of the medical professionals and parents facing this clinical situation, sometimes complicated by legal constraints.

Single fetal demise in monochorionic twins: How to predict cerebral injury in the survivor co‐twin?

“…To identify predictors of neurological sequel is the mainstay for ensuring proper parental counseling. 14 In our series, 14 of 68 (20.1%) survivors showed severe cerebral damage: six of 68 cases (8.82%) were diagnosed prenatally and eight of 68 (11.8%) were postnatally mainly related to preterm birth.…”

“…Six cases of prenatal brain injury were diagnosed: in three of them s‐IUFD occurred between 23 and 31 weeks of pregnancy. There is no risk stratification regarding the occurrence of cerebral lesions; however, according to reported data, it seems that the critical period would be from 24 to 34 weeks of gestation, when the impact of cerebral lesions is amplified by the immaturity of the fetal brain 14 …”

“…however, according to reported data, it seems that the critical period would be from 24 to 34 weeks of gestation, when the impact of cerebral lesions is amplified by the immaturity of the fetal brain. 14 Complicated MC pregnancies, like TTTS and s-IUGR, are associated with higher risk of antenatal cerebral injury, even in those cases with double survival, thus the combination of both factors (s-IUFD in the context of TTTS or s-IUGR) may increase the risk of brain damage. In our series, IUGR type III was diagnosed in 50% of cases with antenatal cerebral damage (3/6) and in one of eight cases of postnatal damage, and TTTS in two of six cases (33.3%) of antenatal cerebral damage and in six of eight (75%) of postnatal damage.…”

“…Also, cerebral damage by neuroimaging (US and/or MRI) does not necessarily imply a long‐term developmental delay. To identify predictors of neurological sequel is the mainstay for ensuring proper parental counseling 14 …”

ISUOG Practice Guidelines (updated): performance of fetal magnetic resonance imaging

“…Fetal MRI has been found to be complementary and clinically informative in monochorionic twin pregnancy after iatrogenic or natural demise of a cotwin, to assess the surviving twin for pathological changes and other risks for brain injury 22 , such as severe fetal growth restriction, maternal hypoxia, thrombocytopenia and infection. In this situation, MRI may be indicated both in the absence of ultrasound abnormalities 23 and on visualization of ultrasound abnormalities, such as ventriculomegaly (Table 1 ), that may be associated with conditions which have an impact on further prognosis.…”