Blood lymphocyte chimerism associated with IVF and monochorionic dizygous twinning: Case report

Abstract

We report on dizygotic (DZ) twins, conceived by IVF and ICSI with assisted hatching, who each had a mixture of 46,XX and 46,XY cells in blood lymphocytes. The female twin had mild genitalia abnormalities but further study revealed anatomically normal reproductive anatomy. Chromosome and fluorescence in situ hybridization studies of buccal, skin and ovarian tissue were normal, as were buccal tissue DNA studies. Fetal ultrasound and fetal membrane pathology were consistent with a monochorionic, diamniotic placenta (MCDAP). These twins thus have blood chimerism but are not chimeric in the other tissues studied. The mechanism for the chimerism could be due to either placental vascular anastamoses (after the development of the haematoblast stem cells) or due to an admixture of trophoblast cells during early blastocyst development. Such trophoblast cell admixtures would be restricted to the extraembryonic tissues so that general physical development in the fetus is normal and without somatic cell chimerism. This case in combination with others previously reported suggests that in IVF conceptions, the prevalence of blood chimerism associated with twinning, and the occurrence of DZ twinning associated with MCDAP, may be higher than previously thought.

Non‐identical monozygotic twins, intermediate twin types, zygosity testing, and the non‐random nature of monozygotic twinning: A review

“…DNA studies of skin fibroblasts showed pure dizygosity without evidence of chimerism. A similar twin pair was reported [Williams et al, 2004], conceived by IVF and intra-cytoplasmic sperm injection (ICSI) with assisted hatching and transfer of two embryos. The placenta was MC by ultrasound, confirmed by pathology.…”

Antenatal Diagnosis of Dizygotic, Monochorionic Twins Following IVF/ICSI

“…As in our case, the majority of those described previously have occurred in the context of infertility treatment with ovarian stimulation and artificial insemination i.e. IVF or IVF + ICSI [3,6,8,9,[11][12][13][14]16]. Typically numerous embryos were transferred simultaneously.…”

“…To date 15 cases of monochorionic, dizygotic twins with chimerism have been described [3][4][5][6][7][8][9][10][11][12][13][14]. Most of these cases were blood chimerisms due to twin-twin transfusion in the presence of a common placenta [3,[5][6][7][8][10][11][12][13]; in this case chromosomal analysis of mucosa or skin biopsy is consistent with phenotypic sex. In the current case FISH was carried out on urothelium from both twins.…”

Chimerism of Buccal Membrane Cells in a Monochorionic Dizygotic Twin

“…However, no MCDZTs with cellular chimerism involving cells other than blood cells have been reported in the literature to date. [2][3][4][5] Here we report a probable first case of MCDZTs with buccal cell chimerism.…”

“…Although various tissues other than blood derived from MCDZTs have been investigated in previous studies, none of these tissues demonstrated chimerism. [1][2][3][4][5] Previous reports thus concluded that chimerism is confined to blood cells and that clinical consequences of chimerism in other tissues would be minimal.…”