Lan Geng1, Jia-Hui Wu1,2, Jia-Qi Luo1, Rang Liu1, Jun-Sheng Li3, Yu Shi1, Amanda Kallen4, Tian-Ren Wang5, Xi Xia6. 1. Center for Reproductive Medicine, Peking University Shenzhen Hospital, Futian District, Shenzhen, 518000, Guangdong, China. 2. Department of Obstetrics and Gynecology, Shenzhen Maternity and Child Healthcare Hospital, Futian district, Shenzhen, 518000, Guangdong, China. 3. Center for Reproductive Medicine, Peking University Third Hospital, Beijing, 100191, China. 4. Division of Reproductive Endocrinology and Infertility, Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, 06510, USA. 5. Center for Reproductive Medicine, Hong Kong-Shenzhen Hospital, Futian District, Shenzhen, 518000, Guangdong, China. 6. Center for Reproductive Medicine, Peking University Shenzhen Hospital, Futian District, Shenzhen, 518000, Guangdong, China. xixia1126@hotmail.com.
Abstract
PURPOSE: To evaluate optimal warming time, the early warming or the routine warming time, for transferring vitrified-warmed and cultured overnight cleavage stage of the slow-growing embryos on day 3 in frozen embryo transfer (FET) cycle. METHODS: This was a retrospective cohort study from January 2017 to July 2018. A total of 705 FET patients aged < 40 years were included and 1486 embryos were formed, of which 1366 embryos were eventually transferred. RESULTS: For slow-growing embryos, the clinical pregnancy rate of early warming group [152/468 (32.5%)] was significantly higher than that of routine warming group (55/235 (23.4%)) [OR 1.39 (CI 1.06-1.81), p = 0.01], while there was no statistically significant difference in pregnancy loss in early warming group [39/170 (22.9%)] versus in routine warming group [16/62 (25.8%)] [OR 0.89 (CI 0.53-1.47), p = 0.65]. CONCLUSION: For slow-growing embryos, higher pregnancy outcomes were shown in early warming strategy as compared to the routine warming, which suggested that the improvement of endometrium-embryo synchronism may correct the time difference brought by the slow-growing embryos.
PURPOSE: To evaluate optimal warming time, the early warming or the routine warming time, for transferring vitrified-warmed and cultured overnight cleavage stage of the slow-growing embryos on day 3 in frozen embryo transfer (FET) cycle. METHODS: This was a retrospective cohort study from January 2017 to July 2018. A total of 705 FET patients aged < 40 years were included and 1486 embryos were formed, of which 1366 embryos were eventually transferred. RESULTS: For slow-growing embryos, the clinical pregnancy rate of early warming group [152/468 (32.5%)] was significantly higher than that of routine warming group (55/235 (23.4%)) [OR 1.39 (CI 1.06-1.81), p = 0.01], while there was no statistically significant difference in pregnancy loss in early warming group [39/170 (22.9%)] versus in routine warming group [16/62 (25.8%)] [OR 0.89 (CI 0.53-1.47), p = 0.65]. CONCLUSION: For slow-growing embryos, higher pregnancy outcomes were shown in early warming strategy as compared to the routine warming, which suggested that the improvement of endometrium-embryo synchronism may correct the time difference brought by the slow-growing embryos.