Re-evaluation of Urinary Trypsin Inhibitor on Pregnancy Course in Patients with Threatened Preterm Delivery : A Single-Center Retrospective Study

Background: We evaluated the necessity of urinary trypsin inhibitor for patients with threatened premature labor. Methods: We enrolled 146 women with singleton pregnancies who were treated for threatened premature labor as inpatients. The uterine cervical length of each patient was ? 25 mm at 22?35 weeks of gestation on transvaginal ultrasonography. The patients were divided into two groups: the urinary trypsin inhibitor group (91 patients treated with urinary trypsin inhibitor daily) or non-urinary trypsin inhibitor group (55 patients not treated with urinary trypsin inhibitor). The childbirth outcomes were retrospectively assessed. Results: The median cervical length measured on the day of admission was almost similar between the urinary trypsin inhibitor and non-urinary trypsin inhibitor groups. Depending on the symptoms of uterine contractions, we determined whether ritodrine hydrochloride and/or magnesium sulfate would be appropriate for treatment. The median gestational week at birth was 38 weeks in the urinary trypsin inhibitor group, and no obvious differences were observed when compared with the non-urinary trypsin inhibitor group. With regard to birth weight, no significant difference was found between the two groups (urinary trypsin inhibitor group, 2776 g; non-urinary trypsin inhibitor group, 2800 g). Conclusion: Our data showed no significant beneficial effects of urinary trypsin inhibitor in the maternal course and delivery outcomes.