Inclusion Criteria:  Patients whose written informed consent approved by the Ethics Committee (EC) has been obtained, after having been duly informed of the nature of the study and voluntarily accepted to participate after being fully aware of the potential risks, benefits and any discomfort involved. Women over the age of 18 at the time of signing the informed consent form. Pregnant women with single gestation between weeks 9 and 14 of gestation.  Exclusion Criteria:  Known malignancy History of organ transplant or bone marrow transplant. Maternal transfusion in the last 8 weeks prior to taking the sample. Early gestational loss Existence of serious or uncontrolled bacterial, fungal or viral infections that, in the opinion of the investigator may interfere with the patient's participation in the study or the evaluation of the results of the study. Other circumstances or difficulties that, in the investigator's opinion, may suppose a risk to the subject or reduce the chances of obtaining satisfactory data to achieve the objectives of the study.