Plasma oxytocin but not prostaglandin F2 alpha metabolite levels at cerclage may predict preterm delivery

• Published in: Obstetrics and gynecology (New York. 1953) Vol. 77; no. 6; p. 879
• Main Authors: Behrens, O, Böhmer, S, Goeschen, K, Fuchs, A R
• Format: Journal Article
• Language: English
• Published: United States 01-06-1991
• Subjects: Dinoprost - blood; Female; Humans; Ligation; Obstetric Labor, Premature - etiology; Oxytocin - blood; Predictive Value of Tests; Pregnancy; Uterine Cervical Incompetence - blood; Uterine Cervical Incompetence - complications; Uterine Cervical Incompetence - therapy; Uterine Contraction - blood
• ISSN: 0029-7844

Plasma oxytocin and prostaglandin F2 alpha metabolite (PGFM) concentrations were measured in 45 patients admitted for cerclage during the second trimester. Samples were collected before, 3 hours after, and 3 days after the Shirodkar procedure. Uterine activity was recorded by external tocography twice daily for 30 minutes. Twenty-eight women with uncomplicated pregnancy and commensurate gestational age served as controls. Cervical length, measured by ultrasonography, was significantly shorter before cerclage (36 +/- 2 mm) than after cerclage (43 +/- 2 mm) or compared with controls (48 +/- 1 mm). Bishop scores ranged from 3-6 (median 4) in the cerclage group and 0-1 (median 0) in controls. Fifteen cerclage patients and one control delivered preterm 5-22 weeks after the procedure. Initial plasma PGFM levels were significantly higher in cerclage patients than in controls. The cerclage procedure caused an immediate rise in plasma PGFM and a subsequent fall below initial levels to control values. Neither the initial levels of PGFM nor the increments 3 hours after cerclage correlated with the outcome of pregnancy. By contrast, plasma oxytocin levels before cerclage were significantly higher in patients who subsequently delivered preterm than in those who delivered at term. Cerclage resulted in a significant fall in plasma oxytocin at 3 hours in patients with preterm delivery, but after 3 days the oxytocin levels had returned to the precerclage values. Patients who had increased uterine contractions had significantly higher plasma oxytocin levels but lower PGFM levels than those without contractions.