Chromosome abnormalities in 1255 cleavage-stage human embryos

Abstract

The relationship was examined between chromosome abnormalities in cleavage stage human embryos and maternal age, embryo morphology and development rate. Embryos that were classified as suboptimal for transfer from patients undergoing IVF treatment were disaggregated, and all or most of their cells were fixed for analysis by fluorescence in-situ hybridization. Chromosomes X, Y, 13, 18 and 21, and in some instances 16 were examined. A total of 731 non-viable embryos was analysed. An increase in chromosome abnormalities with decreasing embryo competence and increasing maternal age was shown. Compared with an earlier study, the major difference was that polyploidy (P<00.01) and aneuploidy were previously more common. After pooling results, it was found that aneuploidy increased with maternal age, from 3.1% in embryos from 20-34 years old patients to 17% in patients 40 years or older. Also, aneuploidy occurred more frequently in embryos with good morphology and development rate than in embryos developing poorly. In contrast, dysmorphic and slowly developing or arrested embryos had significantly more polyploidy and mosaicism than normally developing embryos. Clear associations between maternal age and aneuploidy, and between cleavage anomalies and mosaicism have been established in non-viable embryos. Arrested embryos were mostly polyploid. Moreover, polyploidy was found more frequently in embryos analysed on day 4, suggesting that developmentally compromised embryos became arrested in extended culture. A slightly higher aneuploidy rate in the earlier study may be attributed to differences in hormonal stimulation, which also resulted in different numbers of oocytes recruited and matured.

In vitro fertilization with preimplantation genetic screening improves implantation and live birth in women age 40 through 43

“…However, morphology alone only poorly predicts potential chromosomal abnormalities in embryos selected for transfer. Numerous studies show a significant proportion of aneuploid embryos are capable of achieving the highest morphology score [1,[8][9][10][11][12] and there is no clear distinction made between chromosomally normal and abnormal embryos by morphology assessment alone [13]. In most recent studies of good prognosis patients, aneuploidy is reported to be as high as 44.9 % of good quality blastocysts biopsied [14].…”

Comparison of Aneuploidy Frequency to Sperm FISH and Sperm Apoptosis Results in Embryos That Lost the Vitality

“…[1][2][3][4][5][6][7][8] Ya pı lan ça lış ma lar da, ile ri an ne ya şı ile anöp lo i di; em bri yo nel ge li şim dur ma sı ile po lip lo i di ve ya vaş ge li şim ile post-ma yo tik kro mo zom ano ma li le ri ara sın da doğ ru dan iliş ki gös te ril miş tir. 4,9 Sperm ler de ya pı lan ça lış ma lar, cin si yet kromo zom la rı ile 21 ve 22 no lu kro mo zom la ra ait anoma li le ri nin sık lı ğı nın yük sek ol du ğu nu gös ter miş-tir. [10][11][12][13][14] Ma yo tik bo zuk luk gös te ren ol gu lar in ce lendi ğin de ise sperm dip lo i di si nin en sık rast la nan kro mo zom bo zuk lu ğu ol du ğu gös te ril miş tir.…”

“…Anöp lo i di nin ne de ni an ne ye bağ lı fak tör ler ola bile ce ği gi bi prob lem ba ba kay nak lı da ola bil mek tedir. 3,9,[29][30][31] Bu ça lış ma da, er ken dö nem de bu lu nan em bri yo lar da ge li şi min dur ma sı nı açık la ma ya ça-lış mak üze re em bri yo nun ken di sin de ve ba ba dan el de edi len sperm ler de araş tır ma plan lan mış tır.…”

Prediction of pregnancy in IVF cycles on the fourth day of ovarian stimulation

“…This improvement in embryo quality is not necessarily related to the number of embryos, and could be explained by the increase of embryos with chromosomal abnormalities in this group. An increase in embryo chromosomal abnormalities in women with advanced age has been reported [22]. This increase in abnormal embryos is related with the increase of chromosomal abnormalities in the oocytes of these patients [23].…”