In the Ramin et al. study,15 the cerclage performed
in two women was placed before 18 gestational
weeks when funneling of membranes was
noted and the cervical length fell below 2.5 cm.
The outcome of these pregnancies was not reported.
Three cerclages were performed in Guzman et al.’s
study16 at a median gestational age of 21 weeks
(range 15–24 weeks), a preoperative cervical length
of 0.56 cm (range: 0.46–1.13 cm), and a gestational
age at delivery of 28 weeks (range: 26–34 weeks’
gestation). In the study of To et al., 17 three patients
with the shortest cervical lengths (6 mm, 14 mm,
and 15 mm) had elective placement of cervical