(B-242) Identification of Infant Congenital Malformations in a Large US Insurance Claims Database

Background: Major congenital malformations (MCM) are malformations with surgical, medical, or cosmetic importance and are often an outcome of interest in studies of drug safety during pregnancy. While the estimated prevalence of MCM among liveborn infants is 3-4%, no high-performing claims-based algorithms have been published for MCM generally. There are a variety of claims-based MCM algorithms in use, and many regulatory-driven studies require adjudication of MCMs using medical records.

Objectives: To describe the prevalence of claims-identified MCM, according to different claims-based algorithms.

Methods: Pregnancies were identified in claims from 01 January 2017 through 31 December 2022 using the Optum Dynamic Assessment of Pregnancies and Infants (DAPI) database. Infants were linked to pregnancies using a common unique family insurance ID and restricted to those enrolling in the insurance plan within one week of birth. MCM algorithms that were assessed included: (A) ≥ 1 International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) Q00-Q89 (congenital malformations); (B) ≥ 1 MCM diagnosis code identified by the New York State Department of Health (NYSDOH) as major, reportable birth anomalies; and (C) ≥ 2 ICD-10-CM Q00-Q99 codes at least 30 days apart excluding those codes deemed by EUROCAT as minor malformations. Prevalence was calculated per 100 infants.

Results: A total of 599,098 infants were identified in Optum DAPI with conception dates between 01 January 2017 and 31 December 2022. The average age of mothers at the time of conception was 31 years. Infants were 51% male and 49% female. The prevalence of any congenital malformation (Algorithm A) was 35 per 100 infants. The prevalence increased over time, from 31 in 2017 to 39 in infants born in 2023. Common minor malformations included plagiocephaly (7 per 100 infants) and ankyloglossia (8 per 100 infants). Using Algorithm B, prevalence of MCM was 17 per 100 infants. Neural tube defects were identified in 0.1 per 100 infants, severe cardiac defects in 0.4 per 100 infants, and cleft lip/palate in 0.2 per 100 infants. Using Algorithm C, the prevalence of MCM overall was 6 per 100 infants.

Conclusions: The prevalence of MCM, as identified by the presence of at least one diagnosis code in claims, is considerably higher than the background population prevalence. However, an algorithm that required ≥ 2 codes and excluded those for minor malformations resulted in prevalence estimates that were similar to the background prevalence. These results may be useful in planning studies which seek to identify and potentially validate infant MCM.