Epidemiology & Public Health

Cervical insufficiency(CI) is one of the most important etiologies which spontaneous late abortion/preterm birth. With the lack of population-based studies focusing on risk factors for CI, diagnosis and treatment are challenging, especially for the incident cases. The aim of this study is to investigate risk factors for incident CI in a population-wide register of deliveries. We identified as cases the first diagnosis of CI in women who delivered in Sweden from 2004–2012 by linking the Swedish Medical Birth Register(SMBR), the Swedish National Patient Register(SNPR). As a control group, we selected a random sample of deliveries during the same period from women who had no diagnosis of CI. Demographic, pregnancy-related, reproductive historic and medical historic characteristics of cases and controls were compared in univariate and multivariate analysis. All data management and analysis were conducted using SAS 9.4.

A total of 822 incident CI deliveries was identified, corresponding to 8.7‰ of all deliveries (n= 940624). In univariate comparisons of the 822 cases to 8220 controls, we found significant differences in maternal age and country of origin. The CI cases had higher parity and higher rates of multiple gestation, assisted reproduction, gestational diabetes and history of cervical operations. The Independent contribution of these factors will be explored and the confounding effect of infertility and mediation effect of IVF will also be discussed. The results will provide evidence to

help clinicians to identify women at risk of CI in time to provide management and treatment that can improve the pregnancy outcome.