(1040) Outcomes with early and late laser for severe Twin Twin Transfusion Syndrome

To determine if laser surgery for severe TTTS at less than 18 weeks or greater than 24 weeks is associated with an increased risk of perioperative complications or poor outcomes. 

Study Design:

Retrospective cohort study of monochorionic diamniotic twin pregnancies that underwent laser for severe TTTS between 2009-2022. Groups were stratified based on gestational age at laser. The “early” laser group had the procedure at < 18 weeks. The “standard” laser group had the procedure between 18-23 weeks 6 days and the “late” laser group had the procedure at > 24 weeks. The groups were compared for baseline pregnancy characteristics and outcomes. Statistical analysis included Mann-Whitney U test for continuous variables and chi-square, or Fisher’s exact test, for categorical variables.

Results:

472 patients underwent laser during the study period including 52 (11%) early, 386 (82%) standard and 34 (7%) late procedures. Baseline pregnancy characteristics were similar between both the early and late groups compared to the standard group except that the late group had a higher Quintero stage and both the early and late groups had a lower proportion of anterior placenta (Table 1). Patients that had an early laser had a lower live birth rate while patients with a late laser had similar outcomes compared to the standard group (Table 2).

Conclusion:

In this cohort, laser at less than 18 weeks was associated with a lower live birth rate despite similar pregnancy baseline characteristics and gestational age at delivery. Conversely, laser at greater than 24 weeks was associated with a higher Quintero stage at the time of the procedure but had comparable outcomes to laser performed between 18 weeks and 23 weeks 6 days.