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Updated: May 20, 2026

Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction
Published on: June 29, 2013
Severe Early-Onset Fetal Growth Restriction: The Yield of Antenatal and Postnatal Genetic Testing
Matthew H Mossayebi1, Sophie J Adams1, Megan E Bunnell1
1Department of Obstetrics and Gynecology, Brigham and Women's Hospital, Boston, Massachusetts, USA.
Objectives:
We evaluated the diagnostic yield of karyotype (KT) and chromosomal microarray (CMA) with isolated severe FGR diagnosed before 32 weeks' gestation. Exome and genome sequencing (ES/GS) level data were available in a subset of this population.
Method:
We performed a retrospective review of singleton pregnancies (delivered 2022-2025) with estimated fetal weight or abdominal circumference < 3rd percentile before 32 weeks' gestation, no sonographic structural anomalies, and diagnostic testing (KT, CMA, ES, or GS) via amniocentesis or cord blood. Cases with abnormal cell-free DNA were excluded.
Results:
Forty cases were included (mean diagnosis 26.8 weeks). Testing was performed via amniocentesis in 42% and cord blood in 58%. All KT (27/40) were normal. CMA (39/40) identified one pathogenic CNV (2.5%) and three (7.5%) variants of uncertain significance (VUS). Four (10%) showed ≥ 1 region of absence of heterozygosity (AOH) > 10Mb; one revealed maternal uniparental disomy of chromosome 6. Sequencing (N = 10) detected one VUS in COL1A1. Acute viral infection was not observed in any of the cases.
Conclusions:
CMA was diagnostic in 2/39 (5.1%) cases, a pathogenic CNV implicating the SHOX gene, and maternal UPD 6, which were consistent with FGR. There was a remarkable rate (10%) of AOH. Further investigation, including placental studies and genome sequencing, may elucidate whether AOH is a contributing factor for FGR.

