Prospective multicenter observational study to further develop and validate a preterm birth risk predictor, using a preterm cutoff at 37 0/7 weeks gestation and at 35 0/7 weeks gestation. A single maternal peripheral blood sample will be collected for analysis. Data related to potential risk factors for preterm birth will be obtained through maternal interview and review of medical records. Subjects will be followed through the delivery process to assess the course of pregnancy, labor, and to document any related maternal complications. Neonatal outcomes will be gathered from the medical record for up to 28 days of life or discharge, whichever occurs first.

Inclusion Criteria:

• Subject is 18 years of age or older
• Subject has singleton gestation
• Subject is able to provide consent
• Gestational age is confirmed by a documented crown rump length on an ultrasound performed at the study site within 6 0/7 weeks and 13 6/7 weeks gestation (first trimester)
• Subject has no signs and/or symptoms of preterm labor and has intact membranes
• Investigator believes subject is willing to comply with study visits and procedures
• Investigator believes the subject's delivery data will be available within 15 business days from delivery, and neonatal data will be available for data collection purposes within 15 business days from discharge

Exclusion Criteria:

• The subject has a planned cesarean section or induction of labor prior to 370/7 weeks of gestation

• The subject has a planned cerclage placement for the current pregnancy

• There is a known or suspected fetal anomaly or chromosomal abnormality

• The subject has had a blood transfusion during the current pregnancy

• The subject has known elevated bilirubin levels (hyperbilirubinemia)

• The subject has taken or plans to take any of the following medications during the current pregnancy:

  • Progesterone or progesterone-derivative medication after 13 6/7 weeks gestation
  • Enoxaparin, heparin, heparin sodium, low molecular weight heparin after first day of last menstrual period

• The subject has participated in, or plans to participate in, an interventional treatment study during the current pregnancy

• The current pregnancy was previously a multiple gestation that is now a single fetus due to reduction, vanishing twin, etc.

Pregnant women, 18 years or older, who are receiving prenatal care.

Data will be shared once it is published.