Real World Data are Not Always Big Data: The Case for Primary Data Collection on Medication Use in Pregnancy in the Context of Birth Defects Research.

Many examples of the use of real-world data in the area of pharmacoepidemiology include "big data" such as insurance claims, medical records, or hospital discharge databases. However, "big" is not always better, particularly when studying outcomes with narrow windows of etiologic relevance. Birth defects are one such outcome, where specificity of exposure timing is critical. Studies with primary data collection can be designed to query details on the timing of medication use, as well as type, dose, frequency, duration, and indication, that can better characterize the "real world". Because birth defects are rare, etiologic studies are typically case-control in design, like the National Birth Defects Prevention Study, Birth Defects Study to Evaluate Pregnancy exposureS, and Slone Birth Defects Study. Recall bias can be a concern, but the ability to collect detailed information on both prescription and over-the-counter medication use and on other exposures such as diet, family history, and sociodemographic factors is a distinct advantage over claims and medical record data sources. Case-control studies with primary data collection are essential to advancing the pharmacoepidemiology of birth defects.

Public health priorities for gastroschisis: Summary of a meeting sponsored by the Centers for Disease Control and Prevention and the March of Dimes.

BACKGROUND: Gastroschisis has increased worldwide over several decades; however, there are significant gaps in understanding risk factors for development of the defect, particularly those that might be modifiable. Despite advances in survival, little is known about longer-term outcomes for affected individuals. METHODS: On April 27- and 28, 2023, the National Center on Birth Defects and Developmental Disabilities at the Centers for Disease Control and Prevention (CDC) and March of Dimes sponsored a meeting entitled "Public Health Priorities for Gastroschisis". The meeting goals were to review current knowledge on gastroschisis, discuss research gaps, and identify future priorities for public health surveillance, research, and action related to gastroschisis. Meeting participants encompassed a broad range of expertise and experience, including public health, clinical care of individuals with gastroschisis, affected individuals and families, and representatives from professional organizations and federal agencies. RESULTS: Several goals were identified for future public health surveillance and research, including focused theory-driven research on risk factors and increased study of longer-term effects of gastroschisis through improved surveillance. Certain public health actions were identified, that which could improve the care of affected individuals, including increased education of providers and enhanced resources for patients and families. CONCLUSIONS: These efforts may lead to an improved understanding of pathogenesis, risk factors, and outcomes and to improved care throughout the lifespan.

Exome sequencing identifies novel genes underlying primary congenital glaucoma in the National Birth Defects Prevention Study.

BACKGROUND: Primary congenital glaucoma (PCG) affects approximately 1 in 10,000 live born infants in the United States (U.S.). PCG has a autosomal recessive inheritance pattern, and variable expressivity and reduced penetrance have been reported. Likely causal variants in the most commonly mutated gene, CYP1B1, are less prevalent in the U.S., suggesting that alternative genes may contribute to the condition. This study utilized exome sequencing to investigate the genetic architecture of PCG in the U.S. and to identify novel genes and variants. METHODS: We studied 37 family trios where infants had PCG and were part of the National Birth Defects Prevention Study (births 1997-2011), a U.S. multicenter study of birth defects. Samples underwent exome sequencing and sequence reads were aligned to the human reference sample (NCBI build 37/hg19). Variant filtration was conducted under de novo and Mendelian inheritance models using GEMINI. RESULTS: Among candidate variants, CYP1B1 was most represented (five trios, 13.5%). Twelve probands (32%) had potentially pathogenic variants in other genes not previously linked to PCG but important in eye development and/or to underlie Mendelian conditions with potential phenotypic overlap (e.g., CRYBB2, RXRA, GLI2). CONCLUSION: Variation in the genes identified in this population-based study may help to further explain the genetics of PCG.