For a study, researchers sought to evaluate the effectiveness of the Zishen Yutai Pill to placebo in terms of live birth rates among women after fresh embryo transfer cycles. They performed a double-blind, multicenter, placebo-controlled, randomized experiment to see if taking the Zishen Yutai Pill would enhance pregnancy outcomes in women who had fresh embryo transfer following IVF or intracytoplasmic sperm injection. The primary outcome was the rate of live births. Rates of implantation, biochemical pregnancy, clinical pregnancy, pregnancy loss, cycle cancellation, and maternal, fetal, and neonatal problems were secondary outcomes. To detect a difference in live birth rates between the Zishen Yutai Pill and placebo, a total sample size of 2,265 women (1:1 in two groups) was used. During the trial, participants were enrolled and randomly assigned to either 5 g of the Zishen Yutai Pill or placebo orally three times each day.

Between April 2014 and June 2017, a total of 2,580 patients were tested. A total of 2,265 patients were randomly assigned: 1,131 to the Zishen Yutai Pill and 1,134 to placebo. The characteristics of the groups were comparable. In an intention-to-treat analysis, the rates of live birth in the Zishen Yutai Pill (ZYP) groups were 26.8% and 23.0%, respectively (rate ratio [RR], 1.16; 95% CI 1.01–1.34; P=.038). The implantation rates in the ZYP and placebo groups were 36.8% and 32.6%, respectively (RR 1.13; 95% CI 1.01–1.25; P=.027). The biochemical pregnancy rate in the ZYP group was 35.5% vs. 31.1% in the placebo group (RR 1.14; 95% CI 1.02–1.28; P=.026). Clinical pregnancy rates were 31.2% in the ZYP group and 27.3% in the placebo group (RR 1.14; 95% CI 1.00–1.30; P=.043). There were no significant between-group differences in pregnancy loss, maternal problems, or newborn difficulties (all P>.05). When compared to a placebo, the Zishen Yutai Pill enhanced the rate of live delivery following fresh embryo transfer.