Distribution of Fetal Anomalies According to International Statistical Classification of Diseases 10th Revision for Congenital Malformations and Chromosomal Defects: A Descriptive Study

Reports on incidence of congenital anomalies may be an underestimation of the problem owing to deficiencies in maintaining birth defect registries, reliable medical records, statistics and uniformity in reporting. International Classification of Diseases and Related Health Problems is a system used to translate diagnosis of disease and other health problems from words into an alphanumeric code to provide a common language to share health information across the globe and forms a foundation for identification of health trends and statistics globally. ICD-10 version for congenital malformations, deformities and chromosomal abnormalities classification has been widely applied in the pediatric age group. This study attempts to extrapolate the utility of this classification in coding fetal anomalies prenatally to provide data on their burden and distribution at a tertiary referral centre. To apply ICD-10 coding system for congenital malformations and chromosomal defects antenatally to study the distribution pattern of fetal anomalies and its correlation with postnatal coding, 150 consenting women with prenatal diagnosis of fetal malformation were recruited over a period of 18 months between March 2017 and October 2018. A provisional ICD-10 code was assigned based on antenatal ultrasound findings which was revised again based on postnatal examination or autopsy. Cases were followed up until termination or postnatal day 28 to study the outcome. Correlation of antenatal coding with postnatal code and pattern of distribution of anomalies was studied. Among the 150 cases recruited, 145 (96.7%) were singleton pregnancies with most cases (130) diagnosed for the first time beyond 20 weeks of gestation. Termination of pregnancy was done in 17 (11.3%) cases and 133 pregnancies were continued and among these, intra-uterine demise occurred in 5 (3.3%) and 128 (85.3%) resulted in live birth. Postnatal surgery was done in 20 cases in the neonatal period. Of the live births, 97 (75.8%) were alive on postnatal day 28, while 23 (18.0%) expired. Multisystem involvement was observed in 41 (27.3%) cases and the others had single organ system anomalies, most commonly involving circulatory (29/19.3%) followed by nervous (27/18%) system. ICD coding was similar antenatally and postnatally in 87(58%) cases. It was almost similar in 38 (25.3%), and, in 25 (16.7%) cases, the code was different. Though commonly applied postnatally, prenatal classification of fetal anomalies can be done using ICD-10 to study the pattern and distribution of malformations. However, due to fallacies in prenatal diagnosis and additional information that can be obtained only postnatally, all the prenatally coded cases have to be reviewed postnatally and revised.