Jemma Evans1, Natalie J Hannan2, Tracey A Edgell3, Beverley J Vollenhoven4, Peter J Lutjen5, Tiki Osianlis4, Lois A Salamonsen6, Luk J F Rombauts4. 1. Uterine Biology, Prince Henry's Institute of Medical Research, Clayton, VIC 3168, Australia Department of Physiology, Monash University, Clayton, VIC 3168, Australia. 2. Uterine Biology, Prince Henry's Institute of Medical Research, Clayton, VIC 3168, Australia Department of Obstetrics and Gynaecology, University of Melbourne, Heidelberg, VIC 3084, Australia. 3. Uterine Biology, Prince Henry's Institute of Medical Research, Clayton, VIC 3168, Australia. 4. Monash Health, Clayton, VIC 3168, Australia Monash IVF, Clayton, VIC 3168, Australia Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC 3168, Australia. 5. Monash IVF, Clayton, VIC 3168, Australia. 6. Uterine Biology, Prince Henry's Institute of Medical Research, Clayton, VIC 3168, Australia Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC 3168, Australia lois.salamonsen@princehenrys.org.
Abstract
BACKGROUND: Improvements in vitrification now make frozen embryo transfers (FETs) a viable alternative to fresh embryo transfer, with reports from observational studies and randomized controlled trials suggesting that: (i) the endometrium in stimulated cycles is not optimally prepared for implantation; (ii) pregnancy rates are increased following FET and (iii) perinatal outcomes are less affected after FET. METHODS: This review integrates and discusses the available clinical and scientific evidence supporting embryo transfer in a natural cycle. RESULTS: Laboratory-based studies demonstrate morphological and molecular changes to the endometrium and reduced responsiveness of the endometrium to hCG, resulting from controlled ovarian stimulation. The literature demonstrates reduced endometrial receptivity in controlled ovarian stimulation cycles and supports the clinical observations that FET reduces the risk of ovarian hyperstimulation syndrome and improves outcomes for both the mother and baby. CONCLUSIONS: This review provides the basis for an evidence-based approach towards changes in routine IVF, which may ultimately result in higher delivery rates of healthier term babies.
BACKGROUND: Improvements in vitrification now make frozen embryo transfers (FETs) a viable alternative to fresh embryo transfer, with reports from observational studies and randomized controlled trials suggesting that: (i) the endometrium in stimulated cycles is not optimally prepared for implantation; (ii) pregnancy rates are increased following FET and (iii) perinatal outcomes are less affected after FET. METHODS: This review integrates and discusses the available clinical and scientific evidence supporting embryo transfer in a natural cycle. RESULTS: Laboratory-based studies demonstrate morphological and molecular changes to the endometrium and reduced responsiveness of the endometrium to hCG, resulting from controlled ovarian stimulation. The literature demonstrates reduced endometrial receptivity in controlled ovarian stimulation cycles and supports the clinical observations that FET reduces the risk of ovarian hyperstimulation syndrome and improves outcomes for both the mother and baby. CONCLUSIONS: This review provides the basis for an evidence-based approach towards changes in routine IVF, which may ultimately result in higher delivery rates of healthier term babies.
Authors: Kate Devine; Matthew T Connell; Kevin S Richter; Christina I Ramirez; Eric D Levens; Alan H DeCherney; Robert J Stillman; Eric A Widra Journal: Fertil Steril Date: 2015-03-23 Impact factor: 7.329