VALENCIA, Spain—Researchers from Italy developed a cell-based noninvasive prenatal test to screen the fetal genome. The test could help reduce the residual risk for fetal pathogenic genomic abnormalities.
It provides a “significant opportunity for the early detection of molar pregnancy” as well as the detection of simultaneous zygosity, fetal sex, and copy number variants in the same cell in twin and higher order multiple pregnancies, according to Francesca Romana Grati, PhD, the chief genomics officer at Menarini Silicon Biosystems, who presented the test at the 20th World Congress in Fetal Medicine.
The test is now being validated in a population of 1500 pregnancies enriched for fetal genomic abnormalities in multiple Italian centers.
Dr. Grati also presented the case of a partial hydatiform mole in a woman aged 38 years. Circulating free DNA testing identified a low-risk male fetus. The ultrasound scan at 12 weeks revealed a thickened placenta of heterogeneous structure with numerous cysts indicative of a partial mole.
The fetus showed multiple abnormalities including myelomeningocele, increased nuchal fold, micrognathia, cleft lip, omphalocele, and malpositioning of both hands with bilateral syndactyly.
Cytogenetic analysis from chorionic villus sampling revealed hydatiform mole 69, XXY. Histopathological evaluation showed typical features of partial hydatiform mole including trophoblastic hyperplasia with focal villous, hydropic changes, and evidence of fetal developmental delay.
The isolated trophoblasts from maternal blood revealed a significantly higher number of isolated circulating extravillous trophoblasts compared to the rest of singleton study and significantly higher DNA content than maternal cells and healthy control pregnancies.
Dr. Grati concluded that the early diagnosis of a hydatiform mole is crucial for optimal prognostics and treatment to prevent gestational trophoblastic neoplasia.
“The described case report shows that the noninvasive detection, at early gestational weeks, of a triploid diandric [partial hydatidiform mole] with [cell-based non-invasive prenatal test] technology has the potential to improve women’s clinical management,” she said. She added that future directions should involve increasing the number of circulating extravillous trophoblasts as an early marker of hypertensive disorder.
A hydatiform mole or molar pregnancy is a gestational trophoblastic disease originating from the placenta that can metastasize.
Grati FR. Isolation and testing of fetal cells from the mother. Oral presentation at: 20th World Congress in Fetal Medicine; June 28, 2023; Valencia, Spain.