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IVF Embryo and Gestational Sac Size Variation at Different Gestations According to Embryo Transfer Date
Sughashini Murugesu1, Amy Shearer, Kristofer Linton-Reid
1Queen Charlotte's and Chelsea Hospital (S.M., A.S., D.B., M.M., C.S., S.S., S.S., T.B.), Department of Metabolism, Digestion and Reproduction (S.M., S.S., T.B.), and Department of Cancer and Surgery (K.L.-R., E.O.A.), Imperial College, London, United Kingdom; and Department of Obstetrics and Gynaecology, University Hospitals Leuven, Leuven, Belgium (T.B.).
None:
(Abstracted from Reprod Biomed Online 2025;51(3):104956, doi:10.1016/j.rbmo.2025.104956) Current guidance from the Royal College of Obstetricians and Gynecologists on the diagnosis of miscarriage includes confirmation with a transvaginal ultrasound with an empty gestational sac measuring 25 mm or more, or an embryo with a crown-rump length (CRL) measuring 7 mm or more with no heartbeat. The National Institute for Health and Care Excellence (NICE) guidelines indicate that a repeat scan should be taken with a minimum interval of 7 days; other evidence shows that a repeated scan at 14 days for an empty gestational sac should be performed to rule out false-positive diagnoses of miscarriage.
