Objective   To analyze annual and cumulative detection rate and three-year outcome of congenital heart disease (CHD) diagnosed within one year after birth among children born during 2012 – 2018 in Ningbo city for developing appropriate measures on diagnosis and treatment of the disease.

  Methods  The data on 28 208 live births during 2012 – 2018 in a district of Ningbo city, Zhejiang province were extracted from a natural birth cohort study conducted in the city. Totally 1 304 cases of CHD diagnosed within one year after birth among the live births were identified and followed up for 3 years after birth to collect the information on their outcomes of CHD. The annual and cumulative detection rate of CHD in the live births were analyzed and the change trend in annual detection rate of CHD were described with annual percentage change using join point regression. Kaplan-Meier survival analysis was used to calculate the duration of spontaneous-healing of CHD and multivariate logistic regression model was adopted to explore factors associated with CHD spontaneous healing of the cases.

  Results  For all the live births, the cumulative detection rate of CHD diagnosed within one year after birth was 4.62 per 100 live births and the annual detection rate for years from 2012 to 2018 were 1.87, 2.58, 3.13, 4.25, 6.20, 6.37, and 8.26 per 100 live births, respectively, indicating an increasing trend. The number (proportion) of top three types of CHD detected were 431 (33.05%) for atrial septal defect, 232 (17.79%) for patent ductus arteriosus and patent foramen ovale, and 196 (15.03%) for atrial septal defect and patent foramen ovale. The cumulative detection rate of CHD diagnosed within 3, 6 , and 12 months after birth were 4.29, 4.51 and 4.62 per 100 live births. Of all the CHD cases, 97.62% were detected within 6 months after birth. The three-year after birth follow-ups revealed that among all the CHD cases, 934 (71.63%) had spontaneous-healing at a median time of 8.6 months (25th percentile: 7.8 months, 75th percentile 9.4 months); 60 (4.60%) underwent surgeries for CHD; 22 (1.69%) died of the disease; 149 (11.43%) were not healed or cured; and 139 (10.66%) were lost or refused to the follow-up. The results of multivariate logistic regression analysis showed that the CHD cases with elder maternal age at the birth were at decreased risk of without spontaneous healing three-year after birth (odd ratio OR = 0.9342, 95% confidence interval 95%CI: 0.893 – 0.974) but the cases with the household registry of other provinces were at an increased risk of the spontaneous-healing compared to the cases with local province household registry (OR = 1.893, 95%CI: 1.459 – 2.456). The time of spontaneous healing of the female cases and the cases with complex CHD were significantly longer than that of male cases and the cases with simple CHD.

  Conclusion  The results of the survey suggest that the CHD surveillance period could be extended to one year after birth among infants, especially among those being female, with younger maternal age at birth or those with household registry other than local province, and more than 70% of the CHD cases diagnosed within one year after birth could have spontaneous healing within three years after birth and this should be concerned in determining the time of surgery for CHD.