Abstract

Background: Monochorionic (MC) twins are at risk of acute exsanguination after single fetal demise (sFD) due to their shared placental circulation, which may result in sequelae for survivors.

Objectives: To evaluate the prevalence of ante- and postnatal brain injury and long-term neurodevelopmental impairment (NDI) in co-twins after sFD. Secondary outcomes were the prevalence of termination of pregnancy (TOP), neonatal death (NND) and potential risk factors for brain injury.

Search strategy: PubMed, Embase, Scopus and Web of Science were searched to identify relevant studies in October 2024.

Selection criteria: Studies reporting MC twin pregnancies with spontaneous sFD. Studies with selective feticide, twin reversed arterial perfusion sequence, twin anaemia-polycythaemia sequence, congenital anomalies, higher-order multiple pregnancies, fetoscopic laser surgery and double fetal demise were excluded.

Data collection and analysis: Systematic review and meta-analysis were performed following the PRISMA and MOOSE guidelines.

Main results: Thirteen studies involving 311 survivors after sFD were included. The prevalence of TOP, NND, brain injury and NDI was 3% (95% CI: 0%-7%), 6% (95% CI: 0%-16%), 27% (95% CI: 18%-37%), 6% (95% CI: 3%-11%), respectively. The median GA at birth in survivors with brain injury was 29 weeks (IQR 27.7-34.1) compared to 36 weeks (IQR: 32.3-37.0) in the overall group of survivors.

Conclusions: Brain injury occurs in one in four survivors and is associated with lower GA at birth, suggesting a double-hit injury due to a combination of exsanguination and (severe) prematurity. NDI occurs in one in 20 survivors, compared to two-thirds of those with brain injury.

Brain Injury and Neurodevelopmental Outcome in Survivors After Spontaneous Single Fetal Demise in Monochorionic Twins: A Systematic Review and Meta-Analysis. BJOG. 2026 Mar;133(4):570-578. doi: 10.1111/1471-0528.70084. Epub 2025 Nov 12