New data from the multicenter assessment of a spontaneous preterm birth risk predictor (Treetop), a large, prospective US study, has demonstrated that the PreTrm biomarker test from Sera Prognostics, Salt Lake City, can be used to predict very preterm birth (defined as infants born before 32 weeks of gestation) as well as increased length of neonatal hospital stay and severe adverse neonatal outcomes.1

PreTrm is a serum-based proteomic test that uses the ratio of insulin-like growth factor-binding protein 4 (IBP4) to sex hormone-binding globulin (SHBG) to predict the risk of preterm birth. It is the only such clinically validated, commercially available blood test. The PreTrm test provides an early and individual risk prediction for preterm birth in asymptomatic, singleton pregnancies.

“The number one complication of pregnancy is preterm birth,” says Glenn Markenson, MD, director of maternal and fetal medicine at Boston Medical Center and an author on the publication. “Despite a keen awareness of the negative consequences of preterm birth, the inability to adequately predict when the majority of women are, in fact, at greatest risk for preterm birth has been a significant barrier to broadly implementing preventive interventions. The Treetop results support the potential of using the IBP4 to SHBG ratio to predict the risk of preterm birth and subsequent adverse neonatal outcomes. The ability to predict this risk is critical for enabling precision care management.”

The multicenter study enrolled 5,011 women across 18 sites nationally, with a preplanned analysis performed on a randomly selected subgroup of 847 women. Key findings from the substudy include:

  • Of infants born to the 847 women in the analyzed subgroup, 21 had evidence of a severe neonatal condition, up to and including death.
  • The IBP4/SHBG ratio was significantly higher in both very preterm births (at 0/7 weeks) and more severe neonatal outcomes.
  • The IBP4/SHBG ratio was significantly predictive of birth at 0/7 weeks among all 847 women, and when analyzed using a previously defined body mass index stratification (22
  • The IBP4/SHBG ratio predicted neonatal outcomes for composite morbidity/mortality scores of ≥3 or 4.
  • The IBP4/SHBG ratio significantly identified women destined to deliver neonates with increased length of hospital stay.

“Effective interventions that can delay or prevent preterm birth in a small fraction of patients carrying a single baby are well known within the maternal-fetal medicine community, but determining which additional women may benefit from these interventions requires validated prognostic tools,” says Gregory C. Critchfield, MD, chairman and chief executive officer of Sera Prognostics. “The Treetop study results add to the growing body of data showing the clinical and scientific validity of Sera’s PreTrm biomarker test as a comprehensive objective method for understanding each woman’s individual risk of preterm birth. Knowledge of a woman’s individual risk can make a difference because it empowers physicians and every expectant mother to work more closely together to address a woman’s risk for early delivery.”

For more information, visit Sera Prognostics.


1. Markenson GR, Saade GR, Laurent LC, et al. Performance of a proteomic preterm delivery predictor in a large independent prospective cohort. Am J Obstet Gynecol. Epub May 17, 2020; doi: 10.1016/j.ajogmf.2020.100140.

Featured image: Shown at 24 hours old, this baby was born preterm and weighs 1 lb 14 oz. He survived to become a healthy boy. Photo © Michele Kemper courtesy Dreamstime (ID 97044980).