[Cell-free DNA fraction: Can it be used to evaluate the risk of obstetrical issues?] / L'ADN fœtal libre circulant : un outil d'évaluation du risque de survenue de complications obstétricales ?

OBJECTIVE: The aim of the study was to evaluate if fetal cell-free DNA (cfDNA) fraction circulating in maternal blood at the beginning of the second trimester is associated with obstetrical complications. METHODS: This is a retrospective unicentric study conducted at the hospital of Poissy Saint Germain between the 1st January 2015, and the 31st. December 2016, Each woman who had a genetic counseling in order to realize a non-invasive prenatal test (NIPT) was included. Only singleton pregnancies with a documented-issue were analysed. The primary criteria was a composite criteria, defined as the occurrence of preeclampsia, in utero fetal growth, or a spontaneous preterm delivery. A descriptive analyse was first conducted, secondly completed by a sub-group one: "high fetal fraction" (>90th percentile) group, "low fetal-fraction" group (<10th percentile) and "medium fetal-fraction" (control group) group. RESULTS: A total of 417 women had a cfDNA test, which was performed at a mean gestational age of 17.1 weeks of gestation. A total of 17% of pregnancies met the primary criteria. Among them, there were 8 (1.9%) pre-eclampsia, 49 (11.8%) intra-uterine growth restriction and 14 (3.4%) preterm births. There was no significant difference for the occurrence of the primary criteria (P>0.99) and of each obstetrical complication between each group. CONCLUSION: Fetal cf-DNA fraction measured at the beginning of the second trimester is not associated with common obstetrical complications.