Cryopreservation of Human Embryos and Oocytes
ABSTRACT A procedure to cryopreserve mammalian embryos resulting in the birth of offspring was first described almost forty years ago. This procedure resulting in the birth of a child was reported 26 years ago. Since then, the preservation of human oocytes and embryos by cooling them to low subzero temperatures has become an integral part of Assisted Reproductive Technologies (ART). Hundreds of thousands of children have now been born after having been cryopreserved as oocytes or embryos. These results owe as much to the fundamental understanding of cryobiology as to the application of reproductive medicine. This brief review summarizes the history of embryo cryobiology, and presents a synopsis of basic cryobiology as it applies to present methods to improve the cryopreservation of human oocytes.
- The Lancet 09/1978; 2(8085):366. · 39.06 Impact Factor
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ABSTRACT: Results of assisted reproductive techniques from treatments initiated in Europe during 2005 are presented in this ninth report. Data were mainly collected from existing national registers. From 30 countries, 923 clinics reported 418 111 treatment cycles including: IVF (118 074), ICSI (203 329), frozen embryo replacement (79 140), oocyte donation (ED, 11 475), preimplantation genetic diagnosis/screening (5846) and in vitro maturation (247). Overall, this represents a 13.6% increase since 2004, partly due to inclusion of 28 417 cycles from Turkey. European data on intrauterine insemination using husband/partner's semen (IUI-H) and donor semen (IUI-D) were reported from 21 countries and included 128 908 IUI-H and 20 568 IUI-D cycles. In 16 countries where all clinics reported to the IVF register, 1115 cycles were performed per million inhabitants. For IVF, the clinical pregnancy rates per aspiration and per transfer were 26.9% and 30.3%, respectively. For ICSI, the corresponding rates were 28.5% and 30.9%. After IUI-H, the clinical pregnancy rate was 12.6% per insemination in women <40. After IVF and ICSI, the distribution of transfer of one, two, three and four or more embryos was 20.0%, 56.1%, 21.5% and 2.3%, respectively. Huge differences exist between countries. The distribution of singleton, twin and triplet deliveries after IVF and ICSI was 78.2%, 21.0% and 0.8%, respectively. This gives a total multiple delivery rate of 21.8% compared with 22.7% in 2004 and 23.1% in 2003. In women <40 years of age, IUI-H was associated with a twin and triplet pregnancy rate of 11.0% and 1.1%, respectively. Compared with earlier years, there was an increase in the reported number of ART cycles in Europe. Although fewer embryos were transferred per treatment, there was a marginal increase in pregnancy rates and a reduction in multiple deliveries.Human Reproduction 02/2009; 24(6):1267-87. · 4.67 Impact Factor
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ABSTRACT: To present a report on assisted reproductive technologies (ART) cycles performed in 2005 in Canada. This is the fifth annual report from the Canadian ART Register (CARTR). Prospective cohort study. Twenty-five of 25 ART centers in Canada. Couples undergoing ART treatment in Canada during 2005. ART treatments, including IVF, intracytoplasmic sperm injection (ICSI), and frozen ET (FET). Clinical pregnancy, live birth, and multiple birth rates. A total of 11,414 ART cycles was reported to CARTR. In 8195 IVF/ICSI cycles using the women's own oocytes, the clinical pregnancy rate per cycle started was 32.1% (37.5% per ET procedure), and the live birth rate was 25.6%; the multiple birth rate per delivery was 30.8%, with a triplet birth rate of 1.4%. IVF was performed in 40% of cycles and ICSI in 60% with similar pregnancy rates. One or two embryos were transferred in 68% of cycles; transferring more embryos did not increase the pregnancy rate. In 301 IVF/ICSI cycles using donor oocytes, the clinical pregnancy rate was 46.5%, and the live birth rate was 35.2%; the multiple birth rate was 33.3%, with no triplet birth. In 2498 FET cycles using the woman's own oocytes, the clinical pregnancy rate was 22.8%, and the live birth rate was 17.4%; the multiple birth rate was 24.5%, with a triplet birth rate of 1.6%. Compared with singletons, babies from multiple births had higher risks for preterm birth, low birth weight, and perinatal death. For 2005, CARTR achieved 100% voluntary participation from Canadian ART centers for the third consecutive year. Clinical pregnancy and live birth rates continued to increase in 2005 compared with previous years.Fertility and sterility 05/2008; 91(5):1721-30. · 3.97 Impact Factor