Repeated cryopreservation is associated with poor pregnancy outcomes after frozen–thawed embryo transfer in women aged < 35 years: a propensity-score matched cohort study
Zengshu Huang, Chunhui Zhang, Nan Wang, Huiqing He, Song Li, Changzhong Li · 2025
Read Repeated cryopreservation is associated with poor pregnancy outcomes after frozen–thawed embryo transfer in women aged < 35 years: a propensity-score matched cohort study by Zengshu Huang, Chunhui Zhang, Nan Wang, Huiqing He, Song Li, Changzhong Li (2025) in the Tower of Babel, a free online library of public-domain works preserved in clean, searchable text. No sign-up. The full text is served as a plain-text file at a predictable URL, where text is present: https://antarctic-labs.com/tower-of-babel/pmc-12729158.txt.
Description
Zengshu Huang and co-authors published this fertility study in 2025. Embryos are often frozen for later transfer, and sometimes thawed ones must be frozen a second time. Clinics worry the extra freeze harms the odds of a baby. The team sifted more than thirteen thousand transfer cycles from one center, spanning 2018 to 2022, and matched like cases against each other.
After matching, 107 cycles used twice-frozen embryos and 214 used once-frozen ones. The twice-frozen group had far lower pregnancy and live birth rates. The harm showed most in women under thirty-five and in single-embryo transfers. Babies who were born looked alike in weight and health. The authors advise clinics to limit second freezes for younger women and to save the best-grade embryos when a refreeze is a must.
Catalog record
| CREATOR | Zengshu Huang, Chunhui Zhang, Nan Wang, Huiqing He, Song Li, Changzhong Li |
|---|---|
| YEAR | 2025 |
| COLLECTION | PAPERS |
| FORMAT | TXT |
| FILE SIZE | 41 KB |
| VERSION | 1.0 |
| LICENSE | CC BY 4.0 |
| RIGHTS | CC BY |
| SOURCE | Europe PMC |