P12.06: Assessment of cervical length prior to laser treatment for twin–twin transfusion syndrome

Abstract

The purpose of this study was to assess the prognostic value of cervical length (CL) in twin–twin transfusion syndrome (TTTS) patients treated with laser therapy (selective laser photocoagulation of communicating vessels, SLPCV). The study period ranged between January 2000 and July 2003. TTTS was diagnosed if the maximum vertical pocket (MVP) measured ≥ 8 cm in one sac and ≤ 2 cm in the other. CL was assessed pre-op by transabdominal and/or transvaginal ultrasound. Preterm labor symptoms (PTL) were assigned if patients had regular uterine contractions that required tocolytic therapy. Data was recorded prospectively. Statistical significance was determined if p < 0.05. A total of 233 patients with TTTS underwent SLPCV during the study period. The mean preop CL was 4.04 ± .7 cm. CL was indirectly correlated with the MVP in the recipient twin's sac (r = − .139, p <.05), but was not correlated with gestational age at delivery (GAdel) nor survival. Patients with PTL (n = 32) had a shorter CL compared to asymptomatic patients (3.53 ± .81 vs. 4.05 ± .71 cm, p <.05), but this was not clinically significant in terms of GAdel nor survival outcomes. Twenty-two patients (9.4%) had a preoperative CL ≤ 2.5 cm, of which 19 underwent cervical cerclage. There was no difference in GAdel [30.4 ± 5.6 (95% CI 27.9–33.0) vs. 31.7 ± 5.1 (95% CI 31.0–32.5) weeks, p = .27] nor at least one survivor (86.6 vs. 88.7%, p = .73) between patients with preoperative CL ≤ 2.5 cm versus those with CL > 2.5 cm. This study showed no correlation between CL and perinatal outcome in TTTS patients treated with SLPCV. The results must be viewed with caution, as the subjects represent those patients stable enough to undergo SLPCV, and all patients with a CL < 2.5 cm were requested to undergo a cervical cerclage. Further analysis is needed to account for selection bias.