TY - JOUR

T1 - Conjoined twins after single blastocyst transfer

T2 - a case report including detailed time-lapse recording of the earliest embryogenesis, from zygote to expanded blastocyst

AU - Grondahl, Marie Louise

AU - Tharin, Julie Elisabeth

AU - Maroun, Lisa Leth

AU - Jorgensen, Finn Stener

PY - 2022

Y1 - 2022

N2 - Conjoined twins are estimated to occur in 1:50 000 pregnancies. Eighteen cases of pregnancies achieved by ART have been published of which three were achieved after single embryo transfer, allowing discussion of embryo characteristics. We report, to the best of our knowledge, the first case of parapagus conjoined twins after ART. Furthermore, this is the first report of conjoined twins with detailed morphokinetics of the earliest embryogenesis from zygote to expanded and hatched blastocyst stage. The case zygote had three refractile bodies, which were all allocated to one blastomere at first cleavage following an asynchronous pronuclei fading. Within 2 h, this blastomere cleaved to four and fragmented. The remaining blastomere cleaved symmetrically and regularly and a blastocyst (score: 4AB) was vitrified 120 h after IVF. Pregnancy was achieved following a frozen-thawed single blastocyst transfer. The etiopathogenetic mechanism of the origin of conjoined twins is unknown and several hypotheses exist. The morphokinetics in the present case and morphology of other reported cases will be discussed in this context.

AB - Conjoined twins are estimated to occur in 1:50 000 pregnancies. Eighteen cases of pregnancies achieved by ART have been published of which three were achieved after single embryo transfer, allowing discussion of embryo characteristics. We report, to the best of our knowledge, the first case of parapagus conjoined twins after ART. Furthermore, this is the first report of conjoined twins with detailed morphokinetics of the earliest embryogenesis from zygote to expanded and hatched blastocyst stage. The case zygote had three refractile bodies, which were all allocated to one blastomere at first cleavage following an asynchronous pronuclei fading. Within 2 h, this blastomere cleaved to four and fragmented. The remaining blastomere cleaved symmetrically and regularly and a blastocyst (score: 4AB) was vitrified 120 h after IVF. Pregnancy was achieved following a frozen-thawed single blastocyst transfer. The etiopathogenetic mechanism of the origin of conjoined twins is unknown and several hypotheses exist. The morphokinetics in the present case and morphology of other reported cases will be discussed in this context.

KW - blastocyst

KW - morphokinetics

KW - time-lapse recording

KW - conjoined twins

KW - asynchronous pronuclei fading

KW - asymmetric division

KW - IN-VITRO FERTILIZATION

KW - TRIPLET PREGNANCY

KW - 1ST-TRIMESTER DIAGNOSIS

KW - IVF

KW - ANNOTATION

KW - FETUSES

KW - STAGE

KW - RISK

U2 - 10.1093/humrep/deac004

DO - 10.1093/humrep/deac004

M3 - Journal article

C2 - 35134933

VL - 37

SP - 718

EP - 724

JO - Human Reproduction

JF - Human Reproduction

SN - 0268-1161

IS - 4

ER -