Elective single versus double blastocyst-stage embryo transfer in women aged 36 years or older: a retrospective cohort study

Abstract

We evaluated if elective single-blastocyst transfer (eSBT) could be adopted in women aged 36 or older. In this retrospective cohort, women aged ≥36 years received IVF ovarian stimulation cycles and had ≥ two blastocysts. A total of 240 women underwent eSBT and 189 double-blastocyst transfer (DBT) in the first transfer cycle. The subsequent frozen-thawed embryo transfer cycles were a combination of single- and double- blastocyst transfers. Analysis was stratified for patients in age groups 36–37, 38–39 and ≥40, considering the quality of the blastocyst transferred. The cumulative live birth rates (cLBR) were 74.2% (178/240) versus 63.0% (119/189) after eSBT versus DBT, respectively (aOR: 1.09 (0.68, 1.75)). Time to live birth did not vary significantly between the two groups (HR: 0.85 (0.68, 1.08)). The total number of children born was 194 after eSBT (162 singletons and 16 pairs of twins) versus 154 (84 singletons and 35 twins) after DBT. The odds ratios for preterm birth (0.37 (0.21–0.64)), and low birth weight (0.31 (0.16, 0.60)) were all lower in eSBT. In women aged ≥36 years, cLBR following single- versus double- blastocyst transfer was comparable while the odds of multiple live births and adverse perinatal outcomes were reduced.

Keywords:

• Elective single-blastocyst transfer
• cumulative live birth rate
• blastocyst
• multiple birth
• perinatal outcomes
• advanced age
• IVF

Acknowledgments

The authors thank Dr. Xiaohua Liu for help with data validation and statistical assistance. We are very grateful to our volunteer patients for taking part in our research. Without the efforts, this research would not have been possible.

Authors contributions

Juanzi Shi and Hui Wang participated on the design of the study. He Cai and Hui Wang collected the data. He Cai conducted the statistical analyses and drafted the initial version of the manuscript with Hui Wang. Ben W. Mol and Stephan Gordts provided important guidance throughout the study process and the manuscript preparation. All authors contributed in the interpretation of the data, revised the manuscript and approved the final article.

Disclosure statement

No potential conflict of interest was reported by the author(s).