Delayed cord clamping and acute twin-to-twin transfusion syndrome in vaginally born monochorionic twins: a single-centre retrospective cohort study

OBJECTIVE: To evaluate the prevalence of acute peripartum twin-to-twin transfusion syndrome (TTTS) in vaginally born monochorionic (MC) twin pregnancies, comparing early cord clamping (ECC) to delayed cord clamping (DCC). DESIGN, SETTING AND PATIENTS: Single-centre retrospective cohort study including vaginally born MC twins at our institution between January 2020 and April 2025. Acute peripartum TTTS was defined as intertwin haemoglobin (Hb) difference >8 g/dL within 12 hours after birth, without signs of chronic TTTS or twin anaemia polycythaemia sequence. Twins were categorised to the ECC and DCC group if cord clamping occurred ≤60 s or >60 s after birth of the first twin, respectively. RESULTS: Thirty-five twin pregnancies were included (n=17 in the ECC group; n=18 in the DCC group). Acute peripartum TTTS occurred in 0% (0/17) in the ECC group compared with 17% (3/18) in the DCC group (p<0.01). In the ECC group, no cases of severe brain injury were observed, whereas 8% (3/36) of infants in the DCC group, all with acute peripartum TTTS, showed severe brain injury (p<0.01). DCC time of the first born infant was associated with larger intertwin Hb difference (β=0.01, p=0.04). Potential risk factors for acute TTTS included interval between birth and cord clamping of the first infant (OR 1.02, 95% CI 1.00 to 1.03, p<0.03) and total combined diameter of bidirectional placental anastomoses (OR 1.34, 95% CI 0.97 to 1.84, p=0.07). CONCLUSION: DCC in MC twin pregnancies may be associated with a higher prevalence of acute peripartum TTTS and severe brain injury and is therefore not recommended.