Prospective investigation of second-trimester thrombin activation and preterm birth

• Published in: American journal of obstetrics and gynecology 2012-04, Vol.206 (4), p.333.e1-333.e6
• Main Authors: Vidaeff, Alex C., MD, MPH, Monga, Manju, MD, Saade, George, MD, Bishop, Karen, BS, Ramin, Susan M., MD
• Format: Article
• Language: English
• Subjects: Adult; Amniocentesis; amniotic fluid; Amniotic Fluid - chemistry; Antithrombin III - analysis; Antithrombin III - biosynthesis; Biological and medical sciences; Case-Control Studies; Diseases of mother, fetus and pregnancy; Enzyme Activation; Female; Gynecology. Andrology. Obstetrics; Humans; Medical sciences; Obstetrics and Gynecology; Peptide Hydrolases - analysis; Peptide Hydrolases - biosynthesis; Pregnancy; Pregnancy Trimester, Second - blood; Pregnancy. Fetus. Placenta; Premature Birth; preterm birth; Prospective Studies; Thrombin - analysis; Thrombin - biosynthesis; thrombin-antithrombin complexes
• ISSN: 0002-9378; 1097-6868
• DOI: 10.1016/j.ajog.2012.02.010

Objective We sought to determine if second-trimester amniotic fluid thrombin-antithrombin (TAT) complexes concentration correlates with subsequent preterm birth. Study Design A cohort of 550 women with singleton nonanomalous pregnancies undergoing second-trimester genetic amniocentesis was followed up to delivery and analyzed as a nested case-control study. Cases of preterm birth (n = 52) were compared with 104 term control subjects. Amniotic fluid collected at amniocentesis was tested for TAT. Results TAT concentrations were significantly higher in women who delivered preterm (median 115.9 µg/L) than in those who did not (median 62.2 µg/L; P < .001). This difference persisted when 31 spontaneous preterm births and 21 indicated preterm births were analyzed separately. The odds ratios for preterm birth in the highest TAT quartile relative to the lowest quartile was 4.98 (95% confidence interval, 1.17–22.01; P = .007). Conclusion We found a difference in the pattern of intraamniotic thrombin generation between women destined to deliver at term and those who deliver preterm, regardless of the type of preterm birth.