The Preterm Prediction Study: Recurrence risk of spontaneous preterm birth

• Published in: American journal of obstetrics and gynecology 1998, Vol.178 (5), p.1035-1040
• Main Authors: Iams, Jay D., Goldenberg, Robert L., Mercer, Brian M., Moawad, Atef, Thom, Elizabeth, Meis, Paul J., McNellis, Donald, Caritis, Steve N., Miodovnik, Menachem, Menard, M.Kathryn, Thurnau, Gary R., Bottoms, Sidney F., Roberts, James M.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; cervical length; Diseases of mother, fetus and pregnancy; fetal fibronectin; Gynecology. Andrology. Obstetrics; Medical sciences; Pregnancy. Fetus. Placenta; Preterm birth
• ISSN: 0002-9378; 1097-6868
• DOI: 10.1016/S0002-9378(98)70544-7

Objective: We sought to estimate the risk of spontaneous preterm birth in parous women by use of obstetric history, fetal fibronectin, and sonographic cervical length. Study Design: The probability of spontaneous preterm birth before 35 weeks' gestation was estimated from a logistic regression model with data from 1282 parous women analyzed according to gestational age at the most recent prior delivery (prior preterm birth at 18 to 26 weeks, 27 to 31 weeks, 32 to 36 weeks, and ≥37 weeks' gestation), fetal fibronectin status (positive = ≥50 ng/dl), and cervical length by percentile groups (≤10th = ≤25 nm, 10th to 50th = 26 to 35 mm, and >50th = >35 mm) measured at 22 to 24 weeks' gestation. Fibronectin and cervical length results were blinded for clinical care. Results: Among fetal fibronectin positive women with a prior preterm birth, the estimated recurrence risk of preterm birth 35 mm. The risk of preterm birth was increased among women with a history of preterm delivery but was not influenced by the gestational age at delivery of the most recent preterm birth. Conclusion: The recurrence risk of spontaneous preterm birth varies widely according to fetal fibronectin and cervical length. Cervical length and fetal fibronectin results had distinct and significant effects on the recurrence risk of preterm birth. Predicted recurrence risk is increased by twofold to fourfold in women with a positive compared with a negative fetal fibronectin, and it increases as cervical length shortens in both fetal fibronectin–positive and fetal fibronectin–negative women. These data may be useful to care for women with a history of preterm birth and to design studies to prevent recurrent premature delivery. (Am J Obstet Gynecol 1998;178:1035-40.)