20-year survival of children born with congenital anomalies: a population-based study

Background: Congenital anomalies are a leading cause of perinatal and infant mortality. Advances in care have improved the prognosis for some congenital anomaly groups and subtypes, but there remains a paucity of knowledge about survival for many others, especially beyond the first year of life. We estimated survival up to 20 years of age for a range of congenital anomaly groups and subtypes.

Methods: Information about children with at least one congenital anomaly, delivered between 1985 and 2003, was obtained from the UK Northern Congenital Abnormality Survey (NorCAS). Anomalies were categorised by group (the system affected), subtype (the individual disorder), and syndrome according to European Surveillance of Congenital Anomalies (EUROCAT) guidelines. Local hospital and national mortality records were used to identify the survival status of liveborn children. Survival up to 20 years of age was estimated by use of Kaplan-Meier methods. Cox proportional hazards regression was used to examine factors that affected survival.

Findings: 13,758 cases of congenital anomaly were notified to NorCAS between 1985 and 2003. Survival status was available for 10 850 (99.0%) of 10 964 livebirths. 20-year survival was 85.5% (95% CI 84.8-86.3) in individuals born with at least one congenital anomaly, 89.5% (88.4-90.6) for cardiovascular system anomalies, 79.1% (76.7-81.3) for chromosomal anomalies, 93.2% (91.6-94.5) for urinary system anomalies, 83.2% (79.8-86.0) for digestive system anomalies, 97.6% (95.9-98.6) for orofacial clefts, and 66.2% (61.5-70.5) for nervous system anomalies. Survival varied between subtypes within the same congenital anomaly group. The proportion of terminations for fetal anomaly increased throughout the study period (from 12.4%, 9.8-15.5, in 1985 to 18.3%, 15.6-21.2, in 2003; p<0.0001) and, together with year of birth, was an independent predictor of survival (adjusted hazard ratio [HR] for proportion of terminations 0.95, 95% CI 0.91-0.99, p=0.023; adjusted HR for year of birth 0.94, 0.92-0.96, p<0.0001).

Interpretation: Estimates of survival for congenital anomaly groups and subtypes will be valuable for families and health professionals when a congenital anomaly is detected, and will assist in planning for the future care needs of affected individuals.

Funding: BDF Newlife.