MRI measurement of residual cervical length after radical trachelectomy for cervical cancer and the risk of adverse pregnancy outcomes: a blinded imaging analysis.

Abstract

Objective To determine the association between the residual cervix measured on postoperative MRI after radical vaginal trachelectomy (RVT) and adverse obstetrical outcomes.Design Observational study.Setting Referral Cancer centre.Population Women who conceived after RVT for cervical cancer at the Royal Marsden Hospital, London, between 1995 and 2015.Methods Postoperative MRI scans were analysed by three researchers. The agreement between researchers was assessed by Pearson's correlation coefficient and Bland-Altman plot. Patients were divided into two groups (<10 and ≥10 mm residual cervix) for the analysis of adverse obstetrical outcomes.Main outcome measures Late miscarriage, premature delivery, premature rupture of membranes (PROM) and chorioamnionitis.Results Thirty-one MRI scans were available; 29 of these women had a pregnancy that progressed beyond the first trimester. There was a strong reproducibility of the measurement of residual cervix (P < 0.001). Nineteen women (65.5%) had <10 mm residual cervix and 10 (34.5%) had ≥10 mm. Among women with <10 mm residual cervix, seven (36.8%) experienced PROM and ten (66.7%) had a preterm birth; No women with ≥10 mm residual cervix had PROM and two (22.2%) had a preterm birth (P = 0.028 and P = 0.035, respectively). Overall, there were nine (16.7%) first-trimester miscarriages, six (11.1%) late fetal losses, 12 (31.6%) preterm births and 36 (66.7%) live births. After a mean follow up of 78.1 months, 36 women were disease-free and one woman had died.Conclusions MRI measurements of the residual cervix are reproducible between observers. The incidence of PROM and premature delivery is higher when the residual cervix after RVT is <10 mm.Tweetable abstract The risk of prematurity after RVT can be predicted from measurements of residual cervical length on postoperative MRI scan.