This study will assess the predictive potential of circulating placental biomarkers for spontaneous miscarriage within the following month in an IVF setting. It is hypothesized that a robust algorithm including one or more of these biomarkers may allow for the accurate same-day distinction between women with a low and high risk of a spontaneous miscarriage.

Spontaneous miscarriage is the most common adverse outcome in the first trimester of pregnancy. This is a particularly stressful situation for the expecting parents, since their need for a final diagnosis is frustrated for a potentially extended period on time which may span over several weeks. The emotional impact of this complication can be devastating, resulting frequently in depression and anxiety which may last for several months.

In an attempt to allow for an earlier and more accurate diagnosis of first trimester miscarriage, multiple circulating placental biomarkers have been tested over last years. However, their potential usefulness in an everyday clinical setting remains unclear.

The investigators propose a single-center observational prospective cohort study in an in vitro fertilization (IVF) setting. All recruited consenting patients will collect blood samples on a day of the first pregnancy test (12-14 days after embryo transfer) and at the time of the first (at 5 weeks plus 4-5 days of gestational age) and second (at 7 weeks plus 4-5 days of gestational age) ultrasound scan to determine the circulating placental biomarkers concentrations in order to predict the pregnancy outcome (spontaneous miscarriage versus evolutive pregnancy) until the first obstetrical ultrasound, performed between 11 weeks and 13 weeks plus 6 days of gestational age.

Inclusion Criteria:

• Age: ≥18 and <49 years old
• Body Mass Index (BMI): ≥18.5 Kg/m2 and <30 Kg/m2
• Pregnancy resulting from Assisted Reproductive Technologies (ART)
• Single blastocyst transfer pregnancy
• Pregnancy confirmed by blood test
• Gestational age < 6 weeks at the first US
• Signed and dated informed consent

Exclusion Criteria:

• Spontaneous pregnancies
• Treatment for prevention of miscarriage (i.e. corticoids, aspirin, heparin)
• Those unable to provide the 11th-13th week ultrasound report
• Those unable to comprehend the investigational nature of the proposed study

120 pregnant subjects, confirmed by blood βhCG test, following vitrified-warmed single blastocyst cycles performing IVF/Intracytoplasmic Sperm Injection (ICSI) with autologous oocytes without preimplantation genetic testing for aneuploidies (PGT-A).