Register based study of anorectal anomalies over 26 years: Associated anomalies, prevalence, and trends.

Background: Anorectal anomalies are atresias or stenoses of the anal canal and rectum with or without fistulous connections with the bladder, urethra, perineum, or vestibule. The aim of this study was to describe the epidemiology of anorectal anomalies, including associated anomalies, prevalence, and temporal trends.

Methods: Anorectal anomalies occurring in late miscarriages (>20 gestation weeks), terminations of pregnancy for fetal anomaly (any gestation), stillbirths (≥24 gestation weeks) and live births, delivered from 1985 to 2010, notified to the Northern Congenital Abnormality Survey (NorCAS) were included in this population-based case series.