Objective: To evaluate whether the fetal fraction of cell-free DNA at the first and second trimesters is associated with spontaneous preterm birth.
Methods: This was a retrospective cohort study with singleton pregnancies who underwent noninvasive prenatal testing. According to pregnancy outcome, eligible patients were divided into a delivery group ≥37 weeks of pregnancy (term group) and <37 weeks of pregnancy (spontaneous preterm group).
Background: Xp22.31 deletion and duplication have been described in various studies, but different laboratories interpret pathogenicity differently.
Objectives: Our study aimed to refine the genotype-phenotype associations between Xp22.