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FRIDAY, June 26, 2020 (HealthDay News)<\/p>\n
Vitrification is a safe way to freeze and store embryos during fertility<\/a> treatment, but the longer embryos are stored, the less likely women are to get pregnant<\/a> and have a live birth, a new study from China suggests.<\/p>\n In vitrification, embryos are briefly placed in a dehydrating solution, then fast-frozen to prevent damaging ice crystals from forming.<\/p>\n Some experts feared the process could be unsafe for the embryo, leading to complications, including preterm birth, low or high birth weight and birth defects<\/a>.<\/p>\n For this study, researchers in Shanghai analyzed data from nearly 24,700 women who had vitrified embryos transferred for the first time between January 2011 and December 2017.<\/p>\n Group one had embryos stored for up to three months; group two embryos had been stored for three to six months; group three embryos were stored six to 12 months; and embryos in group four had been stored one to two years.<\/p>\n The embryo implantation rate fell from 40% in group one to 26% in group four, while the clinical pregnancy<\/a> rate fell from 56% in group one to 26% in group four. The live birth rate fell from 47% in group one to 26% in group four.<\/p>\n There was no evidence that storage time affected infant outcomes, according to the study published June 24 in the journal Human Reproduction<\/i>.<\/p>\n Study co-author Qifeng Lyu is deputy director of the Department of Assisted Reproduction at Shanghai Ninth People’s Hospital.<\/p>\n While the study suggests that storage time had a negative effect on implantation and live birth rates, Lyu said it demonstrated the safety of using long-stored vitrified embryos on newborn<\/a> health.<\/p>\n “This is reassuring news for couples seeking fertility<\/a> treatment. The reduction in live birth rates can be overcome through additional embryo transfer cycles. If we had found that neonatal<\/a> health was adversely affected by vitrification, it would impose a heavy burden on individuals, family and society,” Lyu said in a journal news release.<\/p>\n Study leader Qianqian Zhu, from the same hospital department, said clinicians should consider the effect of storage time before deciding how many embryos to freeze and store.<\/p>\n “This is especially important for cancer<\/a> patients, who may have their ovaries destroyed by cancer<\/a> therapies and who have to delay fertility treatment until they have recovered from their disease,” Zhu said.<\/p>\n — Robert Preidt<\/p>\n ![\"MedicalNews\"](\"https:\/\/images.medicinenet.com\/images\/HealthDay\/healthday.png\")
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