P –775 Obstetric and perinatal outcomes of singleton pregnancies after blastocyst-stage embryo transfer: a systematic review and cumulative meta-analysis

AbstractStudy questionAre obstetric/perinatal outcomes different in singleton pregnancies following blastocyst-stage embryo transfer when compared to cleavage-stage embryo transfer and have results changed over time?Summary answerPregnancies following blastocyst are consistently associated with higher risk of large for gestational age and lower risk of small for gestational age babiesWhat is known alreadyExtended embryo culture to blastocyst-stage is widely used to select best embryos in in vitro fertilisation (IVF) cycles to improve pregnancy rates. Transfer of blastocyst-stage embryos is increasing with this being the default strategy in most clinics. As blastocysts are kept in culture until day 5, 6 or 7 after oocyte fertilisation, there are suggestions that longer exposure to culture media may have a negative impact on pregnancy outcomes. More recent primary studies have challenged some of the initial findings. We therefore conducted an updated systematic review and cumulative meta-analysis (CMA) to examine if these results have changed over time.Study design, size, durationSystematic review of studies published between 1980 and 2020, followed by aggregated meta-analysis and CMA to track the accumulation of evidence over the period of time. Exposed group: singleton pregnancies following blastocyst transfer. Non-exposed group: singleton pregnancies following cleavage-stage transfer. Sub-group analyses were conducted on fresh and frozen-thawed embryo transfers. Perinatal (c...
Source: Human Reproduction - Category: Reproduction Medicine Source Type: research