The effect of indomethacin tocolysis on maternal coagulation status

Objective: To investigate the effect of indomethacin tocolysis on maternal coagulation. Methods: Twenty gravidas at 24-32 weeks’ gestation were treated for preterm labor with 50 mg indomethacin orally, followed by 25 mg every 6 hours for 3 days. Bleeding time, prothrombin time (PT), and activated partial thromboplastin time (aPTT) were measured before and 48 hours after initiation of therapy. Statistical analysis was performed by paired t test and Fisher exact test. Results: The typical participant was 22 years old, nulliparous, and 26.2 weeks’ gestational age at enrollment. The mean bleeding time was 4.5 minutes before therapy and 8.8 minutes after therapy (P <.0001, mean difference 4.3 minutes, 95% confidence interval 2.9-5.8). Nineteen of the 20 subjects experienced an increase in bleeding time and 13 had abnormal bleeding times. No clinically significant changes in PT or aPTT were noted. The mean period from treatment to delivery was 60.2 days. No cases of neonatal intraventricular hemorrhage or maternal postpartum hemorrhage were noted. Conclusion: Oral indomethacin treatment for tocolysis has no impact on PT and aPTT; however, profound acute changes in maternal bleeding time occur.