- Title:
- Transfer of Fresh versus Frozen Embryos in Ovulatory Women
- Journal:
- N Engl J Med 2018; 378:126-136
- Author(s):
- Shi Y1, Sun Y1, Hao C1, Zhang H1, Wei D1, Zhang Y1, Zhu Y1, Deng X1, Qi X1, Li H1, Ma X1, Ren H1, Wang Y1, Zhang D1, Wang B1, Liu F1, Wu Q1, Wang Z1, Bai H1, Li Y1, Zhou Y1, Sun M1, Liu H1, Li J1, Zhang L1, Chen X1, Zhang S1, Sun X1, Legro RS1, Chen ZJ1.
- Author(s) affiliation:
- 1From the Center for Reproductive Medicine, Shandong Provincial Hospital-Shandong University, the Key Laboratory of Reproductive Endocrinology of Ministry of Education, and the National Research Center for Assisted Reproductive Technology and Reproductive Genetics (Y. Shi, D.W., Z.W., M.S. H. Liu, J.L., L.Z., Z.-J.C.), and the Center for Reproductive Medicine, Qilu Hospital of Shandong University (X.D.), Jinan, the Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, and Shanghai Key Laboratory of Assisted Reproduction and Reproductive Genetics (Y. Sun, Z.-J.C.), and the Shanghai Jiai Genetic and IVF Center, Obstetrics and Gynecology Hospital, Fudan University (X.S.), Shanghai, the Center for Reproductive Medicine of Yantai Yuhuangding Hospital, Yantai (C.H.), the Center for Reproductive Medicine, Tianjin Central Hospital of Obstetrics and Gynecology, Tianjin (Y. Zhang), the Department of Reproductive Endocrinology, Women's Hospital (Y. Zhu, D.Z.), and the Center for Reproductive Medicine (S.Z.), School of Medicine, Zhejiang University, Hangzhou, the Affiliated Hospital of Qingdao University (X.Q.) and the Center for Reproductive Medicine, Qingdao Women and Children's Hospital-Qingdao University (Y. Zhou), Qingdao, the Center for Reproduction and Genetics, Suzhou Municipal Hospital, Suzhou (H. Li), the Department of Reproductive Medicine, First Affiliated Hospital of Nanjing Medical University-Jiangsu Province Hospital, Nanjing, (X.M.), the Reproductive Medicine Center of Jinghua Hospital, Shenyang (H.R.), the Center for Reproductive Medicine, Wuhan University, Wuhan (Y.W.), the Reproductive Medicine Research Center, 6th Affiliated Hospital of Sun Yat-sen University (B.W.), the Center for Reproductive Medicine, Women and Children's Hospital of Guangdong Province (F.L.), and the Center for Reproductive Medicine, Sun Yat-sen Memorial Hospital of Sun Yat-sen University (X.C.), Guangzhou, the Center for Reproductive Medicine, Maternal and Child Health Care Hospital of Jiangxi Province, Nanchang (Q.W.), the Center for Assisted Reproduction, Northwest Women and Children's Hospital, Xi'an (H.B.), and the Center for Reproductive Medicine, Beijing Chaoyang Hospital, Beijing (Y.L.) - all in China; the Department of Biostatistics, Yale University School of Public Health, New Haven, CT (H.Z.); and the Department of Obstetrics and Gynecology, Penn State College of Medicine, Hershey, PA (R.S.L.).
- Background:
- Elective frozen-embryo transfer has been shown to result in a higher live-birth rate than fresh-embryo transfer among anovulatory women with the polycystic ovary syndrome. It is uncertain whether frozen-embryo transfer increases live-birth rates among ovulatory women with infertility.
- Methods:
- In this multicenter, randomized trial, we randomly assigned 2157 women who were undergoing their first in vitro fertilization cycle to undergo either fresh-embryo transfer or embryo cryopreservation followed by frozen-embryo transfer. Up to two cleavage-stage embryos were transferred in each participant. The primary outcome was a live birth after the first embryo transfer.
- Results:
- The live-birth rate did not differ significantly between the frozen-embryo group and the fresh-embryo group (48.7% and 50.2%, respectively; relative risk, 0.97; 95% confidence interval [CI], 0.89 to 1.06; P=0.50). There were also no significant between-group differences in the rates of implantation, clinical pregnancy, overall pregnancy loss, and ongoing pregnancy. Frozen-embryo transfer resulted in a significantly lower risk of the ovarian hyperstimulation syndrome than fresh-embryo transfer (0.6% vs. 2.0%; relative risk, 0.32; 95% CI, 0.14 to 0.74; P=0.005). The risks of obstetrical and neonatal complications and other adverse outcomes did not differ significantly between the two groups.
- Conclusions:
- The live-birth rate did not differ significantly between fresh-embryo transfer and frozen-embryo transfer among ovulatory women with infertility, but frozen-embryo transfer resulted in a lower risk of the ovarian hyperstimulation syndrome. (Funded by the National Key Research and Development Program of China and the National Natural Science Foundation of China; Chinese Clinical Trial Registry number, ChiCTR-IOR-14005406.)
- Link to the journal
Abstract taken from PubMed
- Abstract :
- Background Elective frozen-embryo transfer has been shown to result in a higher live-birth rate than fresh-embryo transfer among anovulatory women with the polycystic ovary syndrome. It is uncertain whether frozen-embryo transfer increases live-birth rates among ovulatory women with infertility. Methods In this multicenter, randomized trial, we randomly assigned 2157 women who were undergoing their first in vitro fertilization cycle to undergo either fresh-embryo transfer or embryo cryopreservation followed by frozen-embryo transfer. Up to two cleavage-stage embryos were transferred in each participant. The primary outcome was a live birth after the first embryo transfer. Results The live-birth rate did not differ significantly between the frozen-embryo group and the fresh-embryo group (48.7% and 50.2%, respectively; relative risk, 0.97; 95% confidence interval [CI], 0.89 to 1.06; P=0.50). There were also no significant between-group differences in the rates of implantation, clinical pregnancy, overall pregnancy loss, and ongoing pregnancy. Frozen-embryo transfer resulted in a significantly lower risk of the ovarian hyperstimulation syndrome than fresh-embryo transfer (0.6% vs. 2.0%; relative risk, 0.32; 95% CI, 0.14 to 0.74; P=0.005). The risks of obstetrical and neonatal complications and other adverse outcomes did not differ significantly between the two groups. Conclusions The live-birth rate did not differ significantly between fresh-embryo transfer and frozen-embryo transfer among ovulatory women with infertility, but frozen-embryo transfer resulted in a lower risk of the ovarian hyperstimulation syndrome. (Funded by the National Key Research and Development Program of China and the National Natural Science Foundation of China; Chinese Clinical Trial Registry number, ChiCTR-IOR-14005406 .).
- Link to the paper on PubMed
