Introduction A large prospective birth cohort study was established in March 2007 to look at health outcomes of 13 000 babies booked for delivery at our hospital. Nearly half the population of babies born in this region have parents of Pakistani ethnicity. These babies are known to have higher prevalence of congenital malformations. We looked at congenital cardiac anomalies & ethnic variation in our cohort and present our preliminary findings.
Methods Data was collected retrospectively on cardiac anomalies in babies from the cohort born between May 2007 and March 2010 using a multiple ascertainment model. Clinicians reported cases, letters from one stop echo clinic and clinic records were searched and babies referred to regional Paediatric Cardiology services were included. We ascribed ethnicity to cases using clinical records and inferred it to the cohort using self defined ethnicity based on first 5000 questionnaire responses. Prevalence was estimated using total number of babies in the cohort as the denominator. χ2 Test was used for statistical analysis.
Results In the study period there were 10 875 participants, of these 5002 were of Pakistani ethnicity. 242 (2.3%) babies so far are known to have congenital anomalies of which 80 (30%) had congenital cardiac anomalies. Estimated prevalence for congenital cardiac anomalies in Pakistani population is 11/1000, in non Asian is 4.4/1000. The prevalence of congenital heart diseases excluding VSDs not requiring surgery were estimated at 8.9/1000 in Pakistani babies and 3.3/1000 in non Asian babies (p<0.0001).
Conclusion Although numbers are small, it appears that there is an excess of congenital heart defects in the Pakistani babies, cyanotic and complex defects are more common in them, but that left heart outflow lesions are not more common.
Our findings indicate the potential burden caused by cardiac defects. Understanding ethnic variation in prevalence of congenital cardiac defects is important clinically, genetically and to know the aetiology. Further work is needed to examine to what extent the whole cohort will demonstrate these preliminary findings and whether potential confounders like deprivation may explain the differential rates.