More than 1.15 million assisted reproductive technology (ART) cycles were carried out across Europe in 2023, setting a new record and resulting in the birth of nearly a quarter of a million children. The preliminary figures, unveiled at the 42nd Annual Meeting of the European Society of Human Reproduction and Embryology (ESHRE) in London, confirm that Europe is performing ART at rates that far outstrip global benchmarks, with an average of 2,547 treatment cycles per million inhabitants—well above the estimated worldwide need of 1,500 cycles per million. The data, submitted by 1,473 fertility centres in 36 European countries, capture a field in the midst of a profound clinical transformation.
Since 1997, the European IVF Monitoring (EIM) Consortium has built one of the most comprehensive and longest-running registries of its kind, documenting more than 15.8 million ART cycles and over 3.27 million ART-conceived infants. This vast dataset reveals not just the sheer scale of reproductive medicine but the subtle, steady shifts in how embryos are created, stored, and transferred. The 2023 results crystallize a trend that has been building for years: the dominance of frozen embryo transfer (FET). Of the nearly 950,000 IVF, intracytoplasmic sperm injection (ICSI), and FET cycles reported, FET accounted for 401,483 cycles — a full 43 percent — dwarfing both conventional IVF (158,649 cycles) and ICSI (388,345 cycles).
This pivot toward cryopreservation is no accident. Vitrification, an ultra-rapid freezing technique that transforms the water inside cells into a glass-like state without forming damaging ice crystals, has revolutionized embryo storage. When an embryo is frozen at the blastocyst stage — typically five or six days after fertilization — survival rates exceed 95 percent upon thawing. This allows clinics to decouple ovarian stimulation from embryo transfer, reducing the risk of ovarian hyperstimulation syndrome (OHSS) and enabling transfer into a more physiologically receptive endometrium during a subsequent natural or artificially prepared cycle. The strategy also facilitates elective single embryo transfer, which has become the cornerstone of safer ART practice.
Stable success rates accompany the expanding FET numbers. Delivery rates per embryo transfer were 24.4 percent for IVF, 23.5 percent for ICSI, and 27.6 percent for FET. Although these per-transfer figures appear modest, crude cumulative live birth rates — which account for all transfers resulting from a single egg retrieval — continue to rise, reflecting improved laboratory conditions, refined embryo selection, and the cumulative benefit of multiple frozen transfers. Delivery rates per aspiration or thawing event underscore the same message: 18.9 percent for IVF, 17.2 percent for ICSI, and 24.7 percent for FET, highlighting the efficiency dividend of freeze-all approaches.
Perhaps the most celebrated safety milestone in the 2023 data is the continued fall in multiple pregnancies. As clinics increasingly transfer a single embryo at a time, the rates of twin and triplet deliveries have dropped to their lowest level since European monitoring began. Multiple gestation is a known driver of preterm birth, low birth weight, and maternal complications, so this decline represents a significant public health gain. The shift was achieved without sacrificing overall effectiveness, a balancing act that reproductive endocrinologists have been refining for more than a decade.
Complications remained rare, though the EIM Consortium cautions that under-reporting is likely. OHSS — a potentially life-threatening systemic condition triggered by the hormonal medications used to stimulate the ovaries, causing fluid shifts and hemoconcentration — was reported in 1,760 cycles (0.18 percent). Bleeding episodes were recorded in 965 cycles (0.10 percent), and infection in 218 cycles (0.02 percent). Tragically, four maternal deaths were reported. These numbers, while low, serve as a reminder that ART is not risk-free, and the drive toward milder stimulation protocols and increased FET use is partly motivated by a desire to eliminate severe OHSS altogether.
Beyond infertility treatment, the 2023 dataset includes more than 32,000 fertility preservation procedures, though reporting for this domain remains incomplete. Egg and embryo freezing for medical or social reasons is growing rapidly, and the registry’s ability to track these interventions will be crucial as demand escalates. At the same time, ESHRE is rolling out the European Monitoring of Medically Assisted Reproduction (EuMAR), a prospective, cycle-by-cycle registry that will capture granular data on every treatment and outcome. EuMAR completed a successful pilot and is now transitioning to a permanent, real-time collection programme designed to strengthen post-market surveillance and long-term follow-up.
“The latest data demonstrate not only the continued high utilisation of ART, but also the ongoing evolution of clinical practice,” said Professor Diane De Neubourg, Chair of the EIM Consortium. “The increase of frozen embryo transfer and continued reduction in multiple embryo transfers reflect a sustained commitment to improving both effectiveness and safety for patients.” Professor Dr Anis Feki, Chair of ESHRE, added that “as we look ahead, the development of the EuMAR registry will provide even more detailed, prospective information to guide the future of medically assisted reproduction.” With over 247,000 babies born in a single year and a data trail stretching back a quarter of a century, Europe’s ART monitoring effort is not only documenting a revolution in family building — it is actively steering it toward ever safer and more effective horizons.
Subject of Research: Trends in assisted reproductive technology (ART) treatment cycles, outcomes, and safety in Europe for the year 2023.
Article Title: Frozen Embryo Transfers Now Dominate IVF as Europe Sets New Record for Assisted Reproduction
News Publication Date: 7 July 2026
Web References: https://www.eshre.eu/
References: Presentation: Assisted Reproductive Technology (ART) in Europe 2023 and development of a strategy of vigilance: preliminary results generated from European registers by the ESHRE EIM consortium. Presented at the 42nd Annual Meeting of ESHRE, London, United Kingdom, 7 July 2026.
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Keywords
Human reproduction, Human fertilization, Embryo implantation, In vitro fertilization, Pregnancy, Frozen embryo transfer, Ovarian hyperstimulation syndrome, Single embryo transfer, Vitrification, ESHRE
