We thank Oyelese and Frusca et al for their interest in our publication “Efficacy of ultrasound-indicated cerclage in twin pregnancies.” We have also been very surprised and somewhat frustrated that no randomized controlled trial (RCT) data has been published in the last 10 years on this topic since the 2005 publication of the metaanalysis of RCTs (not designed for twin gestations) of 49 twin pregnancies that showed ultrasound-indicated cerclage (UIC) was associated with a 215% increased risk of preterm birth (PTB) at <35 weeks of gestation and a trend toward higher perinatal mortality rate. Based on this information, Rafael et al, the American College of Obstetricians and Gynecologists, and Berghella et al recommended against the use of UIC in twins in clinical practice, which we still believe is the current correct approach, given the limited RCT data.

We get asked at all conferences on this topic about UIC in twins: it is an unresolved issue, and we do need more data, as Oyalese et al and Ghi et al state, before any final recommendation. That is what we are trying to provide, but we need other research teams to study this issue. Spurred by questions from clinicians, we published a new metaanalysis using individual twin-specific patient-level data, reevaluating the same 49 twins with short transvaginal ultrasound cervical length of <25 mm who were assigned randomly to UIC vs no UIC; after adjustment for confounders, there were no statistically significant differences in PTB at <34 weeks of gestation (adjusted odds ratio, 1.17; 95% confidence interval, 0.23–3.79), other PTB cut-offs, or neonatal outcomes, except for very low birthweight and respiratory distress syndrome, which were significantly higher in the UIC group than in the control group. Unfortunately, these data remain the only RCT data available on UIC in twin gestations.

Apart from our new data, other retrospective studies have been published on the safety and efficacy of UIC in twins, with diverse results. Overall, the limited RCT and non-RCT data are inconclusive for a final and strong recommendation. We agree with both Oyalese et al and Ghi et al, who call for new RCT data. We have been begging for new RCTs on UIC in twins for 10 years now. Unfortunately, no such trials are on-going or planned, according to www.controlled-trials.gov . We are currently conducting an RCT on pessary for twins with short cervical length and an RCT on physical examination-indicated cerclage in twins. Depending on the results of pessary trials for twins with short cervical length, we still hope to do an RCT on UIC on twins in the future. But we are confident this debate in the literature and at conferences will finally spur OTHERS to also start RCTs on UIC in twin gestations. They are ethical, feasible, and urgently needed. Our patients deserve better RCT evidence on this important, often vital issue.