Early laser surgery not linked to preterm delivery, reduced neonatal survival in TTTS

Laser surgery for twin–twin transfusion syndrome (TTTS) before 18 weeks of gestation does not appear to result in preterm delivery, preterm premature rupture of membranes (PROM) or reduced neonatal survival as compared with operation at or after 18 weeks, a cohort study has shown.

Patients with TTTS undergoing laser photocoagulation of placental anastomoses (LPA) at two institutions were included in this study.

The investigators conducted regression analysis to examine the association between early LPA and the study outcomes, adjusted for Quintero stage, selective foetal growth restriction (estimated foetal weight or birthweight discordance ≥25 percent and <10th percentile), gestational age at delivery, maternal age ≥35 years, body mass index >35kg/m², placental location and preterm PROM.

Cox proportional hazard model was used in survival analysis to assess the interval from surgery-to-delivery according to the timing of LPA, while adjusting for confounding variables.

Of the 418 TTTS patients, 68 (16.3 percent) underwent early LPA. The overall rates of delivery were 22.7 percent, 39.6 percent and 53.4 percent at <28, 30 and 32 weeks, respectively. Survival of both twins to 30 days of life was 90.9 percent, while that of at least one twin was 67.2 percent.

There were no significant differences seen between early LPA and LPA ≥18 weeks in terms of the following: delivery rate <28 (19.1 percent vs 23.4 percent; p=0.4), 30 (38.2 percent vs 39.9 percent; p=0.7) and 32 (44.1 percent vs 55.2 percent; p=0.1) weeks, preterm PROM rate (29 percent vs 24.2 percent; p=0.4), or in the proportion of dual twin survival (63.9 percent vs 67.8 percent; p=0.6) or survival of at least one foetus (91.8 percent vs 90.7 percent; p=0.8) to 30 days of life.

Early LPA, compared to LPA ≥18 weeks, correlated with longer surgery-to-delivery interval (median, 106 days [range, 2–164] vs 69.3 days [range, 0–146]; p<0.001), while adjusting for confounding variables (hazard ratio, 2.7, 95 percent confidence interval, 1.9–3.9; p<0.001). In the regression model, early LPA also did not lead to very preterm delivery, preterm PROM or decreased neonatal survival.