Objective: To examine the influence of fetal and maternal characteristics on the survival of children born with Down syndrome.
Methods: We used prospectively collected population-based data on Down syndrome extracted from the UK Northern Congenital Abnormality Survey (NorCAS), January 1, 1985-December 31, 2003, matched to hospital and national mortality records to January 29, 2008, to determine survival status of liveborn children. Survival to 20 years was estimated by using Kaplan-Meier methods. Cox proportional hazards regression was used to examine factors that predict survival.
Results: A total of 1115 Down syndrome pregnancies were notified to NorCAS during the 19 years, a total prevalence of 16.8 (95% CI, 15.8-17.8) per 10,000 live births and stillbirths. Of these, 5.4% resulted in a spontaneous fetal loss (late miscarriage ≥ 20 weeks and stillbirth), 31.7% in a termination of pregnancy, and 63.0% in a live birth. Survival status was known for 95.3% of live births; 16.6% resulted in a death. Year of birth (P < .001), gestational age at delivery (P < .001), standardized birth weight (P < .001), karyotype (P < .01), and presence of additional structural anomalies (P < .001) were significant predictors of survival. Infant gender, plurality, maternal age, and maternal deprivation were not significant predictors of survival.
Conclusions: These robust estimates of predictors of survival are important for the prenatal counseling of parents whose pregnancy is affected by Down syndrome and for health care planning for the future care needs of these children.