Cerebral Lesions at Fetal Magnetic Resonance Imaging and Neurologic Outcome After Single Fetal Death in Monochorionic Twins

Early detection of ischemic brain injuries by diffusion-weighted imaging after radiofrequency ablation for fetal reduction in monochorionic pregnancies

BACKGROUND

This study aimed to investigate the additional advantages of magnetic resonance imaging (MRI), particularly diffusion-weighted imaging (DWI) over fetal ultrasound in the detection of acute ischemic cerebral injuries in complicated monochorionic (MC) pregnancies that underwent selective reduction by radiofrequency ablation (RFA).

METHODS

This prospective cohort study was conducted on 40 women with complicated MC pregnancies who were treated by RFA. Fetal brain imaging by DWI and conventional MRI was performed either in the early (within 10 days after RFA) or late phase (after 3-6 weeks) in the surviving fetuses to detect both acute and chronic ischemic injuries. The presence of anemia after RFA was also evaluated by Doppler ultrasound.

RESULTS

Overall, 13 of the total 43 fetuses (30.23%) demonstrated MRI abnormalities with normal brain ultrasound results including germinal matrix hemorrhage (GMH), extensive cerebral ischemia, and mild ventriculomegaly. Although seven fetuses with GMH eventually survived, fetuses that demonstrated ischemic lesions and ventriculomegaly on MRI died in the uterus.

CONCLUSION

The absence of abnormal cerebral lesions or anemia on ultrasound and Doppler exams does not necessarily rule out fetal brain ischemia. Performing early MRI, particularly DWI seems to be a reasonable option for detection of early intracranial ischemic changes and better management of complicated multiple pregnancies which were treated by RFA.

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

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 Intrauterine Death in Twins: The Importance of Fetal Order

Perinatal mortality is higher in twins. Effects of twin order have not previously been studied in the context of single fetal demise. Our objective was to determine whether death of the fetus more proximal to the cervix will result in worse perinatal outcomes. Our population included multiple pregnancies with two viable fetuses confirmed prior to 20 weeks' gestation with the subsequent death of at least one twin. All the pregnancies were managed at The Royal Women's Hospital, Melbourne between 2006 and 2014. We excluded pregnancies of higher order multiples, the death of both twins simultaneously, and cases with incomplete outcome data. Maternal and neonatal data were reviewed. Of 46 pregnancies included, in 24 (52%), the dead twin was presenting. Gestational age at delivery was significantly earlier in these cases (mean difference: -5.0 weeks, 95% CI [-7.4, -2.6], p < .001), and emergency cesarean rates were higher 67% versus 32% (OR 4.29, 95% CI [1.25, 14.7], p = .02). There were no differences in the frequency of chorioamnionitis, preterm prelabor rupture of membranes, or placental abruption. Survival rates for co-twins were similar in both groups (presenting 83%; not presenting 91%; OR 0.41, 95% CI [0.07, 2.50], p = .29). The increase in neonatal morbidities was related to prematurity rather than to order. Findings were more common in dichorionic twins. Analysis was limited by a small sample size. If the dead twin is presenting, delivery is likely to occur earlier, with associated morbidity for the survivors. This is especially relevant for dichorionic twin pregnancies.

Influence of chorionicity and gestational age at single fetal loss on risk of preterm birth in twin pregnancy: analysis of STORK multiple pregnancy cohort

OBJECTIVE

Single intrauterine death (sIUD) in twin pregnancy is associated with a significant risk of cotwin demise and preterm birth (PTB), especially in monochorionic (MC) twins. However, it is yet to be established whether the gestational age at loss may influence the pregnancy outcome. The aim of this study was to explore the risk of PTB according to the gestational age at diagnosis of sIUD.

METHODS

This was a cohort study of all twin pregnancies booked for antenatal care in a large regional network of nine hospitals over a 10-year period. Ultrasound data were matched to hospital delivery records and to a mandatory national register for stillbirth and neonatal loss provided by the Centre for Maternal and Child Enquires. Cases with double fetal loss at the time of the scan and cases of sIUD occurring at or after 34 weeks of gestation were not included in the analysis. The relative risk (RR) of PTB at < 34, < 32 and < 28 weeks of gestation in twin pregnancies complicated by sIUD was assessed and compared with that in twin pregnancies without fetal loss. The risk of PTB at < 34 weeks was stratified according to the gestational age at diagnosis of sIUD. The risk of PTB in twin pregnancy after sIUD according to the gestational age at death was also explored.

RESULTS

The analysis included 3013 twin gestations (2469 dichorionic (DC) and 544 MC). Median gestational age at birth was lower in the pregnancies complicated by sIUD compared with those that were not (32.0 weeks: interquartile range (IQR), 29.0-34.3 weeks vs 36.7 weeks: IQR, 35.0-37.6; P < 0.001) and this difference persisted when stratifying the data according to chorionicity (P < 0.0001 for both MC and DC pregnancies). The risk of PTB at < 34 weeks (RR, 4.3 (95% CI, 3.5-5.2)), < 32 weeks (RR, 6.1 (95% CI, 4.6-8.1)) and < 28 weeks (RR, 12.4 (95% CI, 6.9-22.2)) of gestation was higher in pregnancies complicated by sIUD compared with those which did not experience fetal loss. This association was observed both in MC and DC twin gestations. When compared with DC pregnancies, MC twins affected by sIUD were not at significantly increased risk of PTB before either 34, 32 or 28 weeks of gestation. The risk of PTB at < 34 weeks of gestation was higher when the sIUD occurred at a later gestational age (chi-square test for trend, P < 0.001).

CONCLUSIONS

Twin pregnancies complicated by sIUD, regardless of the chorionicity, have a significantly higher risk of PTB at < 34, < 32 and < 28 weeks of gestation. The risk of PTB at < 34 weeks of gestation was higher when the sIUD occurred in the second half of the pregnancy. Large prospective multicenter studies with shared protocols for prenatal management are needed to ascertain the actual risk of spontaneous PTB in twin pregnancies affected by sIUD. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.