First trimester ultrasound in the age of cell-free DNA screening: What are we missing?

OBJECTIVES: To evaluate the utility of first trimester (FT) ultrasound (US) between 10 and 14 weeks gestation in identifying fetal findings that would impact clinical management. METHODS: We performed a retrospective review of FT US associated with an abnormal ICD-10 code from August 2016 to December 2018. Results of FT US, genetic testing, and management decisions were abstracted from the electronic health record. RESULTS: A total of 20,594 FT US were performed within our study period, representing 6064 unique patients. Of these, 278 ultrasounds were noted to have fetal findings (278/6064, 4.6%). The most frequent fetal findings were fetal demises (98/278, 35.3%), followed by increased NT/cystic hygroma (67/278, 24.1%), and multiple anomalies (35/278, 12.6%). There was a significant difference between the frequency of fetal findings between patients considered advanced maternal age (AMA) and those who were not (p = 0.017). However, there was no significant difference in the frequency of specific anomalies between these two groups (p = 0.103). CONCLUSION: FT US provides clinical information outside the scope of cfDNA screening in both AMA and non-AMA populations regarding viability and fetal anatomy. Earlier detection of these findings is crucial to allow for the opportunity of informed discussion of testing strategy and decision making.

Utility of expanded carrier screening in pregnancies with ultrasound abnormalities.

OBJECTIVE: Explore the utility of expanded carrier screening in evaluating heritable causes of congenital anomalies detected by prenatal ultrasound. METHOD: A retrospective chart review was conducted to collect structural abnormality and genetic testing data on infants who were evaluated postnatally by a medical geneticist. These were used to determine if expanded carrier screening could have determined the etiology prior to delivery. Additionally, recessive and X-linked conditions on clinically available carrier screening panels were evaluated to determine the number of conditions associated with abnormal ultrasound findings. RESULTS: Our retrospective chart review found 222 patients with genetic etiologies, including eight unique autosomal recessive conditions and six X-linked conditions in the 23% who underwent exome sequencing. Of these 14 unique conditions detected, three were included on a list of 271 conditions for which screening was available in 2019 and five were included on a 500 condition panel available in 2020. A literature review was performed on the list of 271 conditions and 88 were reported to be associated with one or more ultrasound abnormalities. CONCLUSION: This study demonstrates limited but potential utility for expanded carrier screening to determine the underlying etiology of congenital anomalies.