P-767 Cumulative live birth rate after IVF - trend over time and the impact of blastocyst culture and vitrification

AbstractStudy questionHas cumulative live birth rate (CLBR) improved over time and which factors are associated with such an improvement?Summary answerDuring 2007-2017, CLBR per oocyte aspiration increased significantly (27.0 % to 36.3 %), in parallel with an increase in blastocyst transfer and cryopreservation by vitrification.What is known alreadyWhile it has been shown that live birth rate (LBR) per embryo transfer (ET) is higher for fresh blastocyst than for fresh cleavage stage embryo transfer, CLBR per oocyte aspiration, including one fresh ET and all subsequent frozen embryo transfers (FET), does not seem to differ between the two culture strategies.Study design, size, durationSTUDY DESIGN, SIZE, DURATION: National register study including all oocyte aspirations performed in Sweden 2007-2017, n  = 124 700. Donation cycles excluded.Participants/materials, setting, methodsData were retrieved from the Swedish National Registry of Assisted Reproduction (Q-IVF). CLBR was defined as the number of deliveries with at least one live birth resulting from one oocyte aspiration, including all fresh and/or frozen embryo transfers within one year. The delivery of a singleton, twin, or other multiples was registered as one delivery. Cryopreservation of cleavage stage embryos was performed by slow freezing and of blastocyst by vitrification.Main results and the role of chanceOverall, the CLBR per oocyte aspiration increased significantly during the study period, from 27.0 % to 36....
Source: Human Reproduction - Category: Reproduction Medicine Source Type: research