The impact of funneling shape on the secondary prevention of spontaneous preterm birth in patients treated with either an Arabin pessary, McDonald cerclage or early total cervical occlusion (ETCO).

OBJECTIVE

Cervical funneling is associated with spontaneous preterm birth (sPTB). The aim of this analysis was to assess the relationship between funneling shape and the response to the McDonald cerclage, the Arabin pessary and the early total cervical occlusion (ETCO).

METHODS

We retrospectively analyzed data of 312 randomly selected singleton pregnancies with cervical shortening <25 mm or normal cervical length and evaluated them according to the progression of funneling: control group (n = 46), cervical shortening without funneling (n = 107), V-shaped funneling (n = 68), U-shaped funneling (n = 47), and prolapse of the amniotic sac (n = 44). We evaluated sPTB rates <34, <28, <32, and <37 weeks as well as prolongation of gestation and birthweight.

RESULTS

Regarding the rate of sPTB <34 weeks there was no statistical significance in either of the comparisons between control group and each of the four risk groups. Regarding prolongation of gestation we demonstrated a statistical significance for all risk groups compared to the control group (all p < .05) with the lowest prolongation rate noted in the group with amnion prolapse and the highest in the group with isolated cervical shortening without funneling. Similarly, progression of funnel shape resulted in an absolute decrease of birthweight for all risk groups compared to the control group, albeit not significant for the group with U-shaped funneling (p = .1058).

CONCLUSION

Independent of the treatment, there was a significant impact of funneling shape on pregnancy duration and birthweight.