冷凍囊胚植入可能比新鮮囊胚植入達更高懷孕率

冷凍囊胚期胚胎植入可能比新鮮囊胚期胚胎植入達到更高懷孕率，
尤其是第6天之囊胚期胚胎
誘導排卵過程可能會對子宮內膜產生不良影響

http://www.ncbi.nlm.nih.gov/pubmed/?term=Fertil+steril+2013%2C+frozen-thawed+embryo+transfer+cycles

Fertil Steril. 2013 Feb;99(2):389-92. doi: 10.1016/j.fertnstert.2012.09.044. Epub 2012 Oct 11.

Matched-cohort comparison of single-embryo transfers in fresh and frozen-thawed embryo transfer cycles.

Shapiro BS, Daneshmand ST, Restrepo H, Garner FC, Aguirre M, Hudson C.

Source

Fertility Center of Las Vegas, Las Vegas, Nevada 89117, USA. bsshapiro@aol.com

Abstract

OBJECTIVE:

To discern the potential effect of ovarian stimulation on implantation potential by comparing ongoing pregnancy rates from matched blastocysts in fresh and frozen-thawed single-embryo-transfer cycles.

DESIGN:

Matched cohort study.

SETTING:

Private fertility center.

PATIENT(S):

Ninety-three matched pairs of single-blastocyst transfer.

INTERVENTION(S):

Fresh and frozen-thawed embryo transfers were matched on embryo parameters and patient age.

MAIN OUTCOME MEASURE(S):

Ongoing pregnancy at 10 weeks' gestation.

RESULT(S):

The fresh and frozen-thawed groups did not differ significantly in blastocyst diameter, inner cell mass size, trophectoderm cell count, patient age, use of genetic screening, or presence of supernumerary embryos. The ongoing pregnancy rate was significantly greater in the frozen-thawed group than in the fresh group for transfers of day 6 blastocysts (54.3% vs. 17.1%, respectively), but not for day 5 blastocysts (60.9% vs. 56.5%, respectively). This resulted in the overall ongoing pregnancy rate to be significantly greater in the frozen-thawed group than in the fresh group (55.9% vs. 26.9%, respectively).

CONCLUSION(S):

Autologous day 6 blastocysts transferred in frozen-thawed cycles have significantly greater chance of viable implantation than morphologically equivalent embryos transferred in fresh cycles. This advantage appears to result from impaired implantation of day 6 blastocysts in fresh transfers after ovarian stimulation, suggesting that embryo-endometrium asynchrony is a major cause of impaired endometrial receptivity after ovarian stimulation.