Document Classification

Section Type: RESULTS

Text: Treatment with 17P significantly reduced the risk of delivery at less than 37 weeks of gestation (incidence, 36. 3 percent in the progesterone group vs. 54. 9 percent in the placebo group ; relative risk, 0. 66 [95 percent confidence interval, 0. 54 to 0. 81]), delivery at less than 35 weeks of gestation (incidence, 20. 6 percent vs. 30. 7 percent ; relative risk, 0. 67 [95 percent confidence interval, 0. 48 to 0. 93]), and delivery at less than 32 weeks of gestation (11. 4 percent vs. 19. 6 percent ; relative risk, 0. 58 [95 percent confidence interval, 0. 37 to 0. 91]).