987 Preoperative factors associated with favorable outcomes following laser surgery for stage I twin-twin transfusion syndrome

Abstract

The optimal treatment strategy for Quintero stage I twin-twin transfusion syndrome (TTTS) remains controversial. Identification of preoperative factors predictive of outcomes after laser surgery would be useful for counseling. The study aim was to report perinatal outcomes of stage I TTTS cases treated with laser, and to ascertain the preoperative factors associated with favorable outcomes Monochorionic diamniotic multiple gestations with a gestational age (GA) between 16 and 26 weeks with Quintero Stage I TTTS that underwent laser surgery between 2006 and 2019 were studied retrospectively. A favorable outcome was defined as dual perinatal survival with delivery at or beyond 32 weeks of gestation. Candidate preoperative factors were identified via bivariate analyses, and multivariate regression analyses were performed to determine if these factors were independently associated with the primary composite outcome. Of 124 stage I TTTS patients that underwent laser surgery, the overall mean (SD) GAs at surgery and at delivery were 21.7 (2.1) and 33.0 (3.6) weeks, respectively. Dual survivorship occurred in 109 cases (87.9%), while 99 (79.8%) cases delivered at or beyond 32 gestational weeks. The composite primary outcome occurred in 73 cases (58.9%). On bivariate analysis of preoperative patient characteristics, donor umbilical artery (UA) intermittent absent end diastolic flow (iAEDF), donor UA systolic velocity/diastolic velocity (SD ratio), estimated fetal weight (EFW) percent discordance, and cervical length were associated with the outcome. Multiple logistic regression modeling identified donor UA forward flow (OR 2.38 [95%CI 1.03-5.56], p=0.0433) and cervical length (cm) (1.43 [95%CI 1.02-2.00], p=0.0395) as the only associated factors, yielding a c-statistic of 0.64. With 88% overall dual survivorship and 33 weeks mean GA at delivery, laser surgery for stage I TTTS remains a reasonable option. Robust predictors of favorable outcomes that could be incorporated into preoperative counseling were not identified.