Determinants of monozygotic twinning in ART: a systematic review and a meta-analysis

Hviid, Kathrine Vauvert Römmelmayer; Malchau, Sara Sofia; Pinborg, Anja; Nielsen, Henriette Svarre

doi:10.1093/humupd/dmy006

Cited by 71 publications

(68 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…There has been consistent evidence of a higher risk of monozygotic twinning following ART compared with natural conception, 1.4% following ART versus 0.4% following natural conception; the high incidence with ART is in agreement with current study findings . This increased risk has been attributed to various underlying factors and processes involved in ART, such as ICSI, assisted hatching, embryo biopsy for pre‐implantation genetic testing for aneuploidies (PGT‐A), monogenic disorders (PGT‐M) and structural chromosomal rearrangements (PGT‐SR), extended embryo culture and embryo cryopreservation . Studies have shown a consistent association between extended embryo culture and embryo splitting .…”

Section: Discussionsupporting

confidence: 87%

“…18,19 This increased risk has been attributed to various underlying factors and processes involved in ART, such as ICSI, assisted hatching, embryo biopsy for pre-implantation genetic testing for aneuploidies (PGT-A), monogenic disorders (PGT-M) and structural chromosomal rearrangements (PGT-SR), extended embryo culture and embryo cryopreservation. 1,4,6,20 Studies have shown a consistent association between extended embryo culture and embryo splitting. 10,21,22 There have been very few studies addressing whether embryo biopsy is a risk factor for monozygotic twinning.…”

Section: Discussionmentioning

confidence: 97%

“…Studies have suggested that certain ART procedures are associated with increased risk of monozygotic twinning . Extended embryo culture and blastocyst stage transfers have been reported to be associated with increased incidence of monozygotic twinning .…”

Section: Introductionmentioning

confidence: 99%

“…Studies have suggested that certain ART procedures are associated with increased risk of monozygotic twinning. [3][4][5][6] Extended embryo culture and blastocyst stage transfers have been reported to be associated with increased incidence of monozygotic twinning. 3 Other ART related techniques such as ovarian stimulation, intracytoplasmic sperm injection (ICSI), assisted hatching and cryopreservation of embryos have also been implicated to carry a risk of monozygotic twinning, although literature has been inconclusive.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Zygotic splitting following embryo biopsy: a cohort study of 207 697 single‐embryo transfers following IVF treatment

Kamath

Antonisamy

Sunkara

2019

BJOG

View full text Add to dashboard Cite

Objective To evaluate the risk of monozygotic splitting with embryo biopsy during in vitro fertilisation (IVF). Design A cohort study. Setting Anonymised assisted reproductive technology national data from the Human Fertilisation and Embryology Authority, UK. Population Women undergoing single‐embryo transfer (SET) following either pre‐implantation genetic testing (PGT) involving embryo biopsy or IVF without PGT. Methods Data on women undergoing SET either following PGT and non‐PGT IVF treatment in 2000–2016 were analysed to compare the risk of zygotic splitting and monozygotic twining. Logistic regression analysis was performed adjusting for potential confounders. Main outcomes Monozygotic spitting, monozygotic twin birth. Results Data comprising a total of 207 697 SET cycles (4544 following PGT and 203 153 following non‐PGT IVF) were analysed. The live birth rate per embryo transfer was 31.9% (95% confidence interval [CI] 30.5–33.2%) following PGT and 26.9% (95% CI 26.7–27.1%) following non‐PGT IVF. The incidence of zygotic splitting following PGT was 2.4% (95% CI 1.7–3.3%) versus 1.5% (95% CI 1.4–1.6%) following non‐PGT IVF. There was a significantly higher risk of zygotic splitting with PGT versus non‐PGT IVF cycles (odds ratio [OR] 1.64, 95% CI 1.19–2.27). The higher risk of zygotic splitting with PGT cycles remained significant after adjusting for potential confounders (adjusted OR 1.51, 95% CI 1.06–2.15). Conclusions The present study demonstrated an increased risk of monozygotic splitting with embryo biopsy. Given the current sparse literature, it is important to accumulate further evidence to validate the findings. Tweetable abstract A likely increased risk of monozygotic splitting following embryo biopsy.

show abstract

Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Zygotic splitting following embryo biopsy: a cohort study of 207 697 single‐embryo transfers following IVF treatment

Kamath

Antonisamy

Sunkara

2019

BJOG

View full text Add to dashboard Cite

show abstract

“…Proposed triggers for splitting include gene mutations, abnormalities in cell surface proteins, and abnormalities in the formation of the zona pellucida (Kilby et al, ; Mercan et al, ; Jim and Berkovich, ). Increased frequency of monozygotic twins is observed after infertility therapy such as intracytoplasmic sperm injection (Sills et al, ; Song et al, ; Hviid et al, ), indicating a possible association of zona pellucida damage and monozygotic twinning. Enders () described that one possible cause for the increase in monozygotic twinning following in vitro fertilization such as assisted hatching is the constriction of the inner cell mass during mechanical hatching of the blastocyst from the zona pellucida as opposed to the natural digesting that occurs in vivo.…”

Section: Etiology and Pathogenesis Of Conjoined Twinsmentioning

confidence: 99%

Two is a Crowd

2019

View full text Add to dashboard Cite

In this article, we provide a comprehensive overview of multiple facets in the puzzling genesis of symmetrical conjoined twins. The etiopathogenesis of conjoined twins remains matter for ongoing debate and is currently cited—in virtually every paper on conjoined twins—as partial fission or secondary fusion. Both theories could potentially be extrapolated from embryological adjustments exclusively seen in conjoined twins. Adoption of these, seemingly factual, theoretical proposals has (unconsciously) resulted in crystallized patterns of verbal and graphic representations concerning the enigmatic genesis of conjoined twins. Critical evaluation on their plausibility and solidity remains however largely absent. As it appears, both the fission and fusion theories cannot be applied to the full range of conjunction possibilities and thus remain matter for persistent inconclusiveness. We propose that initial duplication of axially located morphogenetic potent primordia could be the initiating factor in the genesis of ventrally, laterally, and caudally conjoined twins. The mutual position of two primordia results in neo‐axial orientation and/or interaction aplasia. Both these embryological adjustments result in conjunction patterns that may seemingly appear as being caused by fission or fusion. However, as we will substantiate, neither fission nor fusion are the cause of most conjoined twinning types; rather what is interpreted as fission or fusion is actually the result of the twinning process itself. Furthermore, we will discuss the currently held views on the origin of conjoined twins and its commonly assumed etiological correlation with monozygotic twinning. Finally, considerations are presented which indicate that the dorsal conjunction group is etiologically and pathogenetically different from other symmetric conjoined twins. This leads us to propose that dorsally united twins could actually be caused by secondary fusion of two initially separate monozygotic twins. An additional reason for the ongoing etiopathogenetic debate on the genesis of conjoined twins is because different types of conjoined twins are classically placed in one overarching receptacle, which has hindered the quest for answers. Clin. Anat. 32:722–741, 2019. © 2019 Wiley Periodicals, Inc.

show abstract

Dichorionic diamniotic twin pregnancy after preimplantation genetic testing and single blastocyst transfer

Huang,

Yan,

Mao

et al. 2024

Birth Defects Research

View full text Add to dashboard Cite

BackgroundIn addition to the potential for multiple pregnancies, natural conception occurring in preimplantation genetic testing (PGT) increases undesired genetic risk. Some studies showed that a dichorionic diamniotic twin pregnancy after a single blastocyst transfer could be caused by embryo splitting or concurrent spontaneous conception.CaseWe describe a patient undergoing PGT who had a dichorionic diamniotic twin pregnancy after single blastocyst transfer in a natural cycle. In this case, we recommended to determine genetic status of the twins by prenatal diagnosis. The results showed that karyotype, chromosome copy number variation, and parental ACAT1 variation of the twins were all normal and similar. To investigate the origin of pregnancy, we used the genotype data of single‐nucleotide polymorphisms typical of genome‐wide association studies. Dizygotic twins were inferred by robust estimation of kinship coefficients, which confirmed the occurrence of a spontaneous conception.ConclusionsThis case strengthens the importance of genetic counseling to inform couples with reproductive genetic risk, such as those who undergo PGT, that intercourse should be avoided, especially in natural transfer cycles. Moreover, prenatal diagnosis remains essential and is strongly recommended to avoid genetic risks.

show abstract

Determinants of monozygotic twinning in ART: a systematic review and a meta-analysis

Cited by 71 publications

References 50 publications

Zygotic splitting following embryo biopsy: a cohort study of 207 697 single‐embryo transfers following IVF treatment

Zygotic splitting following embryo biopsy: a cohort study of 207 697 single‐embryo transfers following IVF treatment

Two is a Crowd

Dichorionic diamniotic twin pregnancy after preimplantation genetic testing and single blastocyst transfer

Contact Info

Product

Resources

About