Real-world prevalence, time of diagnosis, and co-occurrence patterns of birth defects in live-born infants, 2014-2020: A health administrative database study in Japan.

BACKGROUND

A study evaluating the real-world prevalence of birth defects (BDs), including co-occurrence patterns, will provide the information required to estimate Japan's true BD prevalence and monitor it. Information such as when infants are diagnosed with BDs is crucial for defining the study population and data collection period in future administrative database studies.

METHODS

This study utilized the DeSC database, a large claims database comprising multiple health insurance schemes. The prevalence of major BDs, including structural congenital malformations (CMs) and chromosomal abnormalities, was determined in infants born between 2014 and 2020 and continuously insured for ≥1 year. The time of the first BD diagnosis and multiple BD patterns were also evaluated.

RESULTS

Among 43,147 infants, 3050 (7.07%) were diagnosed with major BDs, and 3002 (6.96%) with major CMs. The circulatory system (2.95%) was the most frequent organ system affected by CMs, followed by CMs and deformations of the musculoskeletal system (1.94%). The cumulative diagnostic rates of BDs and CMs at month 6 were 85.9% and 85.6%, respectively. The EUROCAT BD subgroups diagnosed in more than 1.0% of the infants were atrial septal defects (1.47%) and patent ductus arteriosus (1.07%). Among the 2997 infants with EUROCAT BDs, 241 (8.04%) were classified as having multiple BDs.

CONCLUSIONS

A large claims database is a valuable resource for evaluating and monitoring the prevalence of BDs, including multiple patterns. At least 1 year since birth should be considered in future administrative database studies evaluating BDs as outcomes.