Unconjugated serum estriol in the prediction of preterm delivery

OBJECTIVE: The objective was to analyze the serum estriol levels among patients with sings and symptoms of preterm labor and/or preterm rupture of membranes. STUDY DESIGN: A prospective study included pregnant women with sings and symptoms of preterm labor. The main end point of the study was the delivery <28 days from testing. RESULTS: 196 patients were included. 116 patients were included in group I (idiopathic preterm labor), 37 patients in group II (PROM) and the control group (group III) consisted of 43 patients. The incidence of preterm delivery was 31% in group I; in the PROM group all the patients delivered preterm. The mean serum estriol levels in all groups were compared regarding delivery <28 days from testing. In group I patients that delivered <28 days had statistically higher serum level of E3 (14.5 ng/ml vs. 11.1 ng/ml, p = 0.03); in group II the mean E3 serum level did not differ significantly (12.5 ng/ml, p = 0.168). The detailed analysis revealed that significant difference was observed in patients tested after completed 30 wk of gestation (15.4 ng/ml vs 12,8 ng/ml, p = 0.043), but not in patients <30 wk of gestation (9,5 ng/ml vs. 10.0 ng/ml, p = 0.842). CONCLUSIONS: The serum level of E3 seems to have prognostic value in the diagnosis of preterm delivery among symptomatic patients after 30 week of gestation.