The Impact of Selective Fetal Growth Restriction or Birth Weight Discordance on Long-Term Neurodevelopment in Monochorionic Twins: A Systematic Literature Review

Abstract

The aim of this review was to assess the impact of selective fetal growth restriction (sFGR) and/or birth weight discordance (BWD) on long-term neurodevelopment in monochorionic (MC) twins. Five out of 28 articles assessed for eligibility were included. One article concluded that the incidence of long-term neurodevelopmental impairment (NDI) was higher in BWD MC twins (11/26, 42%) than in BWD dichorionic (DC) (5/38, 13%) and concordant MC twins (6/71, 8%). BWD MC twins had a 6-fold higher risk of cerebral palsy compared to DC twins (5/26, 19% vs. 1/40, 3%, p < 0.05). Another article described a linear relationship between birth weight and verbal IQ scores, demonstrating a 13-point difference for a 1000 gram BWD between the twins, with a disadvantage for the smaller twin (p < 0.0001). Three articles analyzing within-pair differences showed that the smaller twin more frequently demonstrated mild NDI (6/80, 8% vs. 1/111, 1%) and lower developmental test scores (up to 5.3 points) as opposed to its larger co-twin. Although these results suggest that MC twins with sFGR/BWD are at increased risk of long-term NDI as compared to BWD DC or concordant MC twins, with a within-pair disadvantage for the smaller twin, the overall level of evidence is of moderate quality. As only five articles with a high degree of heterogeneity were available, our review mainly demonstrates the current lack of knowledge of the long-term outcomes of MC twins with sFGR/BWD. Insight into long-term outcomes will lead to improved prognostics, which are essential in parent counseling and crucial in the process of forming a management protocol specifically for twins with sFGR to optimally monitor and support their development.

Impact of different prenatal management strategies in short‐ and long‐term outcomes in monochorionic twin pregnancies with selective intrauterine growth restriction and abnormal flow velocity waveforms in the umbilical artery Doppler: a retrospective observational study of 108 cases

“…Following SFLC, EM and CC, respectively, children born following different management strategies differed significantly by their gestational age at birth: median 29 (range 29-32), 31 (28)(29)(30)(31)(32)(33)(34)(35)(36) and 34 (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39) weeks. There was no difference in severe or mild NDI, need for special care or sensory deficit between management strategies.…”

“…This appears to be the largest cohort with long-term NDO assessment in type II sIUGR following interventional and expectant management. [29][30][31][32][33] Nonetheless, given its retrospective design, this study has limitations. Counselling was based upon individual risk-benefits ratio and was not standardised.…”

“…The predictive value of a positive a-wave in the DV on the survival of both twins is a consensual finding. 17,19,31,32 A discordance in EFW of less than 25% could seemingly be predictive of the survival of the smaller twin. 18,39 Finally, spontaneous improvement of UA Doppler was also predictive of dual survival in our study except for two cases.…”

Critical Coarctation of the Aorta in Selective Fetal Growth Restriction and the Role of Coronary Stent Implantation

“…Long-term neurodevelopment was favorable in the majority of twins. It is known that the risk of long-term neurological or cognitive impairment in monochorionic twins with sFGR or with a large birth weight discordance is higher than in uncomplicated monochorionic or dichorionic twins, with a disadvantage for the smaller twin [35]. In our cohort, 6 of the 7 growth restricted twins had a normal neurodevelopment.…”

Monochorionic Twins: A Delicate Balance

“…Ideally, the optimal management strategy should be based not only on reliable data on chances of survival but also on chances of disease-free survival (i.e., without cerebral injury and long-term neurodevelopmental impairment). As shown by Groene et al in a systematic review in this edition, knowledge on the long-term outcome in survivors with sFGR is unfortunately very limited [10]. We urgently need high-level evidence to guide us on the optimal management, including the best timing of delivery and reliable data to inform parents of the long-term outcome for both the growth-restricted infant and the appropriately-grown co-twin.…”