OBJECTIVE To measure changes in the posterior fossa of first-trimester fetuses with trisomy 18, trisomy 13 and triploidy. METHODS Brain stem (BS) diameter and BS to occipital bone (BSOB) diameter were measured in images of the midsagittal view of the face at 11(+0) to 13(+6) weeks from 45 trisomy 18, 21 trisomy 13 and 15 triploid fetuses and compared with values in 162 euploid fetuses. RESU...

Phorbol ester (PMA) in concentration 5 and 10 ng ml-1 blocks cytokinesis of the second maturation division in mouse oocytes. Karyokinesis is not impaired and digynic triploid oocytes are obtained which undergo first cleavage division. Effectiveness of blocking cytokinesis is dependent on the timing of exposure of oocytes to PMA action. When oocytes are subjected to PMA at the onset of the secon...

HKJGOM 2005; 5 (1) 33 Introduction The most frequent foetal chromosomal abnormalities involve the autosomes 21, 18, 13 and sex chromosomes X and Y. Aneuploidy or alterations in copy number of these chromosomes, including Trisomy 21 (Down syndrome), Trisomy 18 (Edwards syndrome), Trisomy 13 (Patau syndrome), 45,X (Turner syndrome), 47,XXY (Klinefelter syndrome) and Triploidy (presence of 3 copie...

We report the occurrence of triploid preimplantation embryos following in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in a woman with two previously-identified triploid conceptuses which spontaneously underwent fetal demise at 10 and 23 weeks' gestation. An error in maternal meiosis II is proposed as the most likely cause.

Between 1 and 4% of human oocytes fertilized in vitro are tripronuclear. It has been reported that these tripronuclear oocytes can develop to grossly normal-appearing morulae and that chromosomally, these embryos could be triploid, diploid, or severely depleted. The etiology and proportion of apparently diploid and aneuploid embryos deriving from tripronuclear human oocytes is unknown. This stu...