I read with great interest the study by Roman et al examining the efficacy of ultrasound-indicated cerclage in twin pregnancies. The authors found that cerclage in asymptomatic twin gestations with a cervical length of <1.5 cm at <24 weeks was associated with an almost 4-week prolongation in gestational age. In addition, there was a significant decrease in spontaneous preterm birth <34 weeks of gestation, as well as a reduction in neonatal intensive care unit admissions. These are welcome findings. Granted, the study was a retrospective cohort study with the limitations inherent to such study designs. Nonetheless, if these results are reproduced and verified in further studies, they have the potential to reduce preterm delivery among twins, a population that has one of the highest risks for preterm birth, but in which, until recently, no therapy has been shown to effectively reduce prematurity.

My concern is that the Society for Maternal-Fetal Medicine (SMFM) has previously strongly warned against cerclage in twins. In fact, the SMFM published a document, “Choosing Wisely: Five Things Physicians And Patients Should Question,” that condemns cerclage in twins, implying that the evidence for harm is very strong. However, the “evidence” on which this condemnation was based is extremely weak due to small numbers. In a recent metaanalysis, there were only 49 sets of twins from 3 separate randomized controlled trials. Those trials used a cervical length of <2.5 cm as a cut-off. It is clear that the issue of cerclage in twins has not been conclusively answered. Otherwise, why would the authors have performed the current study?

I do understand our growing desire for good evidence to guide our clinical practice and to help achieve best outcomes. My concern is that in our enthusiasm for such evidence, we may be premature and hasty in making categorical recommendations. Similar concerns have been recently voiced regarding new recommendations on labor duration. I would suggest that until evidence is absolutely clear and unequivocal, strong recommendations should not be made. It is possible that countless women with twins and short cervices measuring <1.5 cm in length may have had needless pregnancy losses or preterm births due to the hasty recommendation not to insert cerclage in twin pregnancy with short cervix. We all look forward to evidence to help us, but we cannot afford to have recommendations made that may later be retracted. The price to pay is too high.