Objective: The presence of sonographic funneling is a co-predictor of spontaneous preterm birth (sPTB). The aim of this study was to assess the outcome in patients with a short cervix and funneling after a McDonald cerclage or an Arabin pessary.
Methods: We retrospectively analyzed data of 238 singleton pregnancies with cervical shortening <25 mm subclassified by either isolated cervical shortening (n = 105) or cervical shortening and additional funneling (n = 133). In the group of isolated cervical shortening, a total of 93 patients had received a cervical pessary and 12 had McDonald cerclage. In the group of patients with additional funneling, 98 had received a cervical pessary and 35 had a cerclage. We evaluated PTB rates <28, <32, <34, and <37 weeks as well as prolongation of gestation, birth weight, and admission to NICU.
Results: In the pessary groups (n = 191), funneling resulted in a significantly higher rate of PTB before 34 weeks as compared to patients with isolated cervical shortening (26.5 versus 8.6%, p=.0066). Similarly, in the cerclage groups (n = 47), funneling resulted in an absolute increase of PTB, albeit not significant (37.1 versus 0%, p=.1435) due to the smaller number. There were no significant differences in terms of prevention of PTB before 34 weeks in patients treated with pessary or cerclage, neither in the group of patients with isolated shortening nor in the group of patients with additional funneling (p=.9771 and p=.3916, respectively). However, in patients with funneling, we demonstrated a significantly lower neonatal admission rate in the pessary arm (n = 27, 27.6%) as compared to the cerclage arm (n = 31, 88.6%) (p = .0002). Similarly, the NICU admission time was shorter in both pessary groups -with and without funneling - as compared to patients treated with cerclage (p = .0000).
Conclusion: Pessary placement and cerclage should optimally be considered before the presence of funneling. Furthermore, there were lower rates of neonatal admission during pregnancy and a shorter admission time of babies after birth when mothers received a cervical pessary as compared to the group with cervical cerclage.
Keywords: Arabin pessary; McDonald cerclage; funneling; secondary prevention; spontaneous preterm birth; transvaginal ultrasound.