胚胎生長速度很關鍵  速度太慢ㄉ胚胎著床率不佳

正常地5天就該形成囊胚  到第7天才形成  染色體多半有問題

Hum Reprod. 2019 Aug 9. pii: dez129. doi: 10.1093/humrep/dez129. [Epub ahead of print]

What is the reproductive potential of day 7 euploid embryos?

Hernandez-Nieto C1, Lee JA1, Slifkin R1, Sandler B1,2, Copperman AB1,2, Flisser E1,2.

Author information

1

Reproductive Medicine Associates of New York, New York, NY, USA.

2

Obstetrics, Gynecology and Reproductive Science, Icahn School of Medicine at Mount Sinai, New York, NY, USA.

Abstract

STUDY QUESTION:

What is the rate of euploidy and the reproductive potential of embryos biopsied after 6 days of development?

SUMMARY ANSWER:

Embryos biopsied after 6 days of development have higher rates of aneuploidy; however, day 7 euploid embryos selected at transfer can achieve acceptable pregnancy rates and live birth (LB) outcomes.

WHAT IS KNOWN ALREADY:

Recent publications have shown promising treatment results after euploid day 7 embryo transfers (ETs), albeit these studies were limited by small sample sizes. Whereas the current clinical standard has been to discard embryos that do not reach expansion by day 6 of development, the lack of robust data surrounding the clinical utility of day 7 embryos warrants further evaluation.

STUDY DESIGN, SIZE, DURATION:

Retrospective cohort analysis in a single, academic in vitro fertilization (IVF) center from January 2012 to March 2018. A total of 25 775 embryos underwent trophectoderm (TE) biopsy and preimplantation genetic testing for aneuploidy (PGT-A). Additionally, the clinical IVF outcomes of 3824 single, euploid frozen embryo transfer (FET) cycles were evaluated.

PARTICIPANTS/MATERIALS, SETTING, METHODS:

Cohorts were segregated by day of TE biopsy following oocyte retrieval (day 5, day 6 or day 7). PGT-A was performed to identify embryonic ploidy rates. Secondly, IVF and LB outcomes after single, euploid FET were evaluated for each cohort.

MAIN RESULTS AND THE ROLE OF CHANCE:

A total of day 5 (n = 12 535), day 6 (n = 11 939) and day 7 (n = 1298) embryos were included in the study analysis. The rate of embryo euploidy was significantly lower in day 7 blastocysts compared to day 5 or day 6 cohorts (day 7 = 40.5%; day 5 = 54.7%; day 6 = 52.9%; (P < 0.0001)). After adjusting for age, anti-Müllerian hormone, BMI, embryo quality and number of embryos biopsied, there was a significant association between aneuploidy and embryos biopsied on day 7 when compared to day 5 biopsied embryos (OR = 1.34, CI 95% 1.09-1.45, P = 0.001) and day 6 biopsied embryos (OR = 1.26, CI95% 1.07-1.16, P < 0.001).A sub-analysis of subsequent 3824 single, euploid FET cycles (day 5: n = 2321 cycles; day 6: n = 1381 cycles; and day 7: n = 116 cycles) showed significant differences among cohorts in implantation, clinical pregnancy, LB and clinical loss rates. There was a significant decrease in the odds of implantation, clinical pregnancy and LB, but no association with clinical loss or multiple pregnancy rates in patients who utilized day 7-biopsied embryos during treatment.