Twin-twin transfusion syndrome (TTTS) is a serious complication in monochorionic twin pregnancies. This condition requires timely intervention, and fetoscopic laser photocoagulation (FLPC) is the definitive treatment in many cases. However, the risk of single fetal demise, particularly the Donor twin demise, remains a significant concern post-surgery. Therefore, identifying preoperative risk factors helps physicians counsel patients and optimize outcomes.
A large retrospective cohort study aimed to identify preoperative factors associated with donor twin demise following laser surgery for TTTS. This significant research included 1602 pregnancies. The study used prospectively collected data from two specialized referral centers between 2006 and 2024. Patients were monochorionic diamniotic pregnancies undergoing FLPC. Furthermore, physicians performed a comprehensive ultrasound and fetal Doppler evaluation, specifically noting the middle cerebral artery peak systolic velocity (MCA-PSV), within 24 hours before the procedure. Ultimately, these findings are crucial for refining risk stratification protocols in TTTS management.
Preoperative Doppler Findings and Donor Twin Demise
The study confirmed several preoperative factors significantly increase the risk of donor fetal death post-laser ablation. Most importantly, an isolated elevation of the donor twin’s MCA-PSV showed the highest adjusted relative risk (aRR, 2.69). This powerful finding suggests impending anemia strongly predicts a poor outcome. Furthermore, a donor MCA pulsatility index below the 10th percentile (aRR, 1.91) proved significant. This doppler result often reflects increased placental resistance. Conversely, Stage III TTTS itself carried a high aRR of 2.34 for the Donor twin demise. In addition, the presence of Twin Anemia-Polycythemia Sequence (TAPS) elevated the risk (aRR, 1.63). Therefore, a comprehensive preoperative Doppler evaluation is a critical step in risk assessment.
Other Anatomical and Gestational Risk Factors
The study also pinpointed other structural and timing-related risk factors for the donor twin. One major anatomical finding was velamentous cord insertion in the donor. This resulted in a notable increased risk (aRR, 1.86). This cord pathology significantly elevates the chance of post-operative demise. Conversely, undergoing surgery at an early gestational age, specifically less than 18 weeks, also showed an independent association (aRR, 1.34). This result confirms that very early laser ablation carries a slightly higher risk. Perhaps this is due to technical limitations or the severity of the underlying disease. In summary, the combination of anatomical, physiological, and gestational factors requires careful consideration during patient counseling.
Frequently Asked Questions
Q1: What was the most significant preoperative risk factor for donor twin demise?
The most significant factor was an isolated elevation of the donor twin’s middle cerebral artery peak systolic velocity (MCA-PSV > 1.5 MoM), which carried the highest adjusted relative risk (aRR, 2.69).
Q2: How does the presence of TAPS affect the donor twin’s survival post-laser surgery?
The study showed that the presence of Twin Anemia-Polycythemia Sequence (TAPS) independently elevated the risk for donor twin demise following fetoscopic laser ablation (aRR, 1.63).
Q3: Are anatomical factors like cord insertion associated with donor demise after laser ablation?
Yes, velamentous cord insertion in the donor twin was identified as a significant anatomical risk factor, showing an adjusted relative risk of 1.86 for post-operative donor demise.
References
- Espinoza J et al. Preoperative factors associated with donor twin demise in 1602 pregnancies complicated by twin-twin transfusion syndrome. Ultrasound Obstet Gynecol. 2025 Dec undefined. doi: 10.1002/uog.70127. PMID: 41189346.
- Baschat AA et al. Donor Death After Selective Fetoscopic Laser Surgery for Twin-Twin Transfusion Syndrome. Obstet Gynecol. 2015 Oct;126(4):780-7. doi: 10.1097/AOG.0000000000000858. PMID: 26241259.
- Alpay K et al. Single fetal demise following fetoscopic ablation for twin-to-twin transfusion syndrome-cohort study, systematic review, and meta-analysis. Am J Obstet Gynecol. 2022 Jul;227(1):101.e1-101.e13. doi: 10.1016/j.ajog.2022.02.035. PMID: 35257668.