This cohort study will examine the clinical utility of genomic sequencing (GS) in patients undergoing prenatal diagnostic procedures (chorionic villus sampling or amniocentesis) for routine indications other than a structural fetal anomaly.

Individuals who request prenatal diagnostic testing with standard chromosomal microarray will be offered GS as an option to assess for additional disease risk. The GS will be limited to evaluation of single gene disorders on a curated gene list developed by our multidisciplinary team of experts. This will include only pathogenic or likely pathogenic variants in genes associated with conditions with a well-defined phenotype that may include cognitive impairment or debilitating health conditions in childhood and/or conditions that will impact maternal, fetal, neonatal, or early childhood health management with significant perinatal or pediatric morbidity or mortality. GS test results will be reported to the research participant by a clinical geneticist or genetic counselor with expertise in exome sequencing. Participants may use this information for pregnancy management including termination of pregnancy. Participants will be offered analysis for secondary findings, as recommended by the American College of Medical Genetics and Genomics. Analysis and reporting of GS will be performed by the UCSF CLIA-certified Genomic Medicine Laboratory. Blood or saliva samples will be collected on both parents to allow trio GS to determine inheritance of any potentially significant fetal variants.

The project is exploratory in nature, with a goal of contributing to a growing body of evidence regarding the clinical utility of GS in the prenatal population.

Inclusion Criteria:

Pregnant patients who are:

• Pregnant with a structurally normal fetus (singleton or multiple gestation)
• Planning to undergo prenatal diagnosis by either chorionic villus sampling or amniocentesis with chromosome microarray analysis for routine indications
• Planning, or have already completed expanded carrier screening

Exclusion Criteria:

Pregnant patients who:

• Decline prenatal diagnostic testing
• Are pregnant and their fetus has a known anomaly
• Declined chromosomal microarray analysis of expanded carrier screening