Interventions to prevent preterm delivery in twin-twin transfusion with short cervix.

Abstract

OBJECTIVE\nPre-operative short cervical length (CL) remains a major risk factor for preterm birth after laser surgery for twin-twin transfusion syndrome (TTTS). Interventions to prolong pregnancy remain elusive. The objective of this study is to compare secondary preventive methods used in the setting of short CL at the time of laser surgery by five North American Fetal Treatment Network (NAFTNet) centers.\n\n\nMETHODS\nA secondary analysis of data collected prospectively at five NAFTNet centers was conducted from January 2011 to March 2020. Inclusion criteria were monochorionic diamniotic twins complicated by TTTS with pre-operative CL <30mm undergoing fetoscopic laser surgery. Treatments for short CL included expectant management, vaginal progesterone, pessary (Arabin, incontinence, or Bioteque cup), cerclage, or a combination of two or more treatments. No patients were on treatment solely for prevention of preterm birth in twins. Demographics, ultrasound characteristics, operative records and outcomes were compared. The primary outcome was procedure to delivery interval.\n\n\nRESULTS\nA total of 255 women were included. Of these, 151 (59%) had expectant management, 32 (13%) had progesterone, 21 (8%) had pessary, 21 (8%) had cerclage and 30 (12%) had a combination. More patients in the combination group had prior preterm birth compared to expectant management (33% vs 9%, p=0.003). Mean preoperative CL was shorter in the pessary, cerclage and combination groups (14-15mm vs 22mm, p<0.001). There was no difference in procedure-to-delivery interval between groups, nor in gestational age at delivery, live birth or neonatal survivors. Using propensity score matching for CL, cerclage was associated with a reduction in procedure-to-delivery interval by 13\u2009days. Progesterone was associated with a decrease in the risk of delivery before 28\u2009weeks of gestation.\n\n\nCONCLUSIONS\nA large proportion of patients had no treatment for short cervix, establishing the high (62%) risk of delivery prior to 32\u2009weeks in this condition. There were no identifiable differences in outcomes among treatments, however there were significant differences in possible confounders including unmeasured ones. A large randomized controlled trial is urgently needed to determine the treatment effects. This article is protected by copyright. All rights reserved.