Guidelines for the number of embryos to transfer following in vitro fertilization: No. 182, September 2006

• Published in: International journal of gynecology and obstetrics 2008-08, Vol.102 (2), p.203-216
• Main Author: JOINT SOGC-CFAS
• Format: Article
• Language: English
• Subjects: Embryo Transfer - methods; Embryo Transfer - standards; Female; Fertilization in Vitro; Humans; Pregnancy; Randomized Controlled Trials as Topic
• ISSN: 0020-7292; 1879-3479
• DOI: 10.1016/j.ijgo.2008.01.007

To review the effect of the number of embryos transferred on the outcome of in vitro fertilization (IVF), to provide guidelines on the number of embryos to transfer in IVF-embryo transfer (ET) in order to optimize healthy live births and minimize multiple pregnancies. Rates of live birth, clinical pregnancy, and multiple pregnancy or birth by number of embryos transferred are compared. Clinical pregnancy, multiple pregnancy, and live birth rates. The Cochrane Library and MEDLINE were searched for English language articles from 1990 to April 2006. Search terms included embryo transfer (ET), assisted reproduction, in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), multiple pregnancy, and multiple gestation. Additional references were identified through hand searches of bibliographies of identified articles. Available evidence was reviewed by the Reproductive Endocrinology and Infertility Committee and the Maternal-Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada and the Board of the Canadian Fertility and Andrology Society, and was qualified using the Evaluation of Evidence Guidelines developed by the Canadian Task Force on the Periodic Health Exam. This guideline is intended to minimize the occurrence of multifetal gestation, particularly high-order multiples (HOM), while maintaining acceptable overall pregnancy and live birth rates following IVF-ET. The recommendations made in this guideline were derived mainly from studies of cleavage stage embryos-those cultured for two or three days. 1. Individual IVF-ET programs should evaluate their own data to identify patient-specific, embryo-specific, and cycle-specific determinants of implantation and live birth in order to develop embryo transfer policies that minimize the occurrence of multifetal gestation while maintaining acceptable overall pregnancy and live birth rates (III-B). 2. In general, consideration should be given to the transfer of fewer blastocyst stage embryos than cleavage stage embryos, particularly in women with excellent prognoses and high-quality blastocysts (I-A). The following recommendations are generally intended for cleavage stage embryos transferred on day two or three. Because blastocyst stage embryos have higher implantation rates than cleavage stage embryos, fewer blastocyst stage embryos may need to be transferred (II). 3. In women under the age of 35 years, no more than two embryos should be transferred in a fresh IVF-ET cycl