Biologic and Genetic Markers

Fetal fibronectin present in cervicovaginal fluids is currently the most powerful biochemical marker of preterm birth.46 Pregnant women who test positive for fetal fibronectin between 24-26 weeks of gestation are at a substantial increased risk for preterm birth.66 There also has been a proposed genetic component to preterm birth. Women whose sisters have given birth preterm have an 80% higher chance of delivering preterm themselves,67 and grandparents of women who deliver preterm are more likely to have been born preterm as well.68 Both maternal and fetal genotypes affect the rates of preterm delivery and may interact with environmental factors such as genitourinary infections, smoking or other risk factors.69-71