囊胚期胚胎, ICM會發展成胎兒, TE cell會發展成胎盤
TE cell 之數量與品質比ICM之數量與品質更能預測胚胎著床率
TE cell 之數量與品質A是男性胎兒機率較高(2.5倍)

J Assist Reprod Genet. 2016 Jan;33(1):49-57. doi: 10.1007/s10815-015-0609-9. Epub 2015 Nov 14.

Quantitative and qualitative trophectoderm grading allows for prediction of live birth and gender.

Ebner T1,2, Tritscher K3, Mayer RB4,5,3,6,7, Oppelt P4,5, Duba HC6, Maurer M6, Schappacher-Tilp G7, Petek E3, Shebl O4,5.

Author information

Abstract

PURPOSE:

Prolonged in vitro culture is thought to affect pre- and postnatal development of the embryo. This prospective study was set up to determine whether quality/size of inner cell mass (ICM) (from which the fetus ultimately develops) and trophectoderm (TE) (from which the placenta ultimately develops) is reflected in birth and placental weight, healthy live-birth rate, and gender after fresh and frozen single blastocyst transfer.

METHODS:

In 225 patients, qualitative scoring of blastocysts was done according to the criteria expansion, ICM, and TE appearance. In parallel, all three parameters were quantified semi-automatically.

RESULTS:

TE quality and cell number were the only parameters that predicted treatment outcome. In detail, pregnancies that continued on to a live birth could be distinguished from those pregnancies that aborted on the basis of TE grade and cell number. Male blastocysts had a 2.53 higher chance of showing TE of quality A compared to female ones. There was no correlation between the appearance of both cell lineages and birth or placental weight, respectively.

CONCLUSIONS:

The presented correlation of TE with outcome indicates that TE scoring could replace ICM scoring in terms of priority. This would automatically require a rethinking process in terms of blastocyst selection and cryopreservation strategy.