(718) Perinatal Outcomes of Resolved Fetal Cystic Hygromas

Friday, January 31, 2025

10:30 AM – 12:30 PM

Submitting Author and Presenting Author(s)

Carmen MA Santoli, MD (she/her/hers)

Maternal Fetal Medicine / Medical Genetics and Genomics Fellow
University Of California San Francisco
San Francisco, California, United States

Coauthor(s)

Emma EH Peek, BS (she/her/hers)

University of Colorado
Aurora, Colorado, United States
LC

Lucas C. Collins, BS

Duke University School of Medicine
Durham, North Carolina, United States
Teresa N. Sparks, MD, MS (she/her/hers)

Associate Professor, Maternal-Fetal Medicine and Clinical Genetics
Center for Maternal-Fetal Precision Medicine, University of California San Francisco
San Francisco, California, United States
JK

Jeffrey A. Kuller, MD

Duke University School of Medicine
Durham, North Carolina, United States
Sarah K. Dotters-Katz, MD

Associate Professor
Duke University School of Medicine
Durham, North Carolina, United States

Objective: We described the perinatal phenotype of pregnancies with resolved fetal cystic hygroma and compared outcomes among fetuses with and without genetic abnormalities.

Study Design: A retrospective cohort study (2013-2023) at a single tertiary center identified fetuses with cystic hygroma in the first or second trimester that resolved on subsequent ultrasound imaging. Pregnancies resulting in live birth with prenatal and delivery data were included. We describe perinatal characteristics, delivery outcomes, and genetic diagnoses. Bivariate statistics compared outcomes among fetuses with and without genetic abnormalities. A p-value < 0.05 was considered statistically significant.

Results: Of 297 fetal cystic hygromas, we identified 59(20%) fetuses with cystic hygromas that resolved on subsequent imaging and resulted in live birth. Of these, 46 pursued prenatal and/or postnatal genetic diagnosis; 31(67%) had normal results and 15(33%) had a genetic abnormality, such as aneuploidy(n=10), copy number variant(n=2), or single-gene disorder(n=3).(Figure) Compared to fetuses with normal genetic testing, fetuses with genetic abnormalities were more likely to have a later gestational age at cystic hygroma diagnosis(12.3 vs 11.6 weeks, p=0.007) and resolution(20.1 vs 17.3 weeks p=0.006).(Table) Compared to fetuses with normal genetic evaluations, fetuses with genetic abnormalities were more likely to have additional structural anomalies on ultrasound(67% vs 13%,p=0.001). The most common ultrasound findings were cardiac anomalies, followed by abdominal and renal abnormalities. Fetuses with resolved cystic hygromas and genetic abnormalities were more likely to have growth restriction, an earlier delivery, longer length of neonatal stay, and neonatal complications.

Conclusion: Fetuses with resolved cystic hygromas and genetic abnormalities were more likely to have other structural anomalies and obstetric complications when compared to those with normal results of genetic testing. These data are important for framing expectations and counseling of patients who experience resolution of fetal cystic hygroma.