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Impact of preimplantation genetic testing on the incidence of monochorionic diamniotic pregnancies in single blastocyst frozen-thawed embryo transfers: a retrospective cohort study spanning 10 years.

Source: PubMed, NCBI / U.S. National Library of Medicine

BMC pregnancy and childbirthTan Jifan, Chen Ruyun, Zheng Zetong, et al.Published 6/6/2026Last synced 6/8/2026Status: syncedPMID: 42251314DOI: 10.1186/s12884-026-09383-9

This study aimed to explore the associations between assisted reproductive technology (ART) modality and chorionicity in monozygotic twinning pregnancies following single blastocyst frozen-thawed embryo transfer. This retrospective cohort study analyzed 30,121 single embryo transfer cycles from January 2013 to December 2022 but focused on 251 monozygotic twinning pregnancies following single blastocyst frozen-thawed embryo transfer, including 144 monochorionic diamniotic (MCDA) twins and 107 dichorionic diamniotic (DCDA) twins. Regression analysis was performed to determine the risk factors for the subtypes of monozygotic twinning pregnancies after ART. Pregnancy complications and neonatal outcomes of the MCDA and DCDA groups were compared, and subgroup analyses among the in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and preimplantation genetic testing (PGT) groups were performed. The overall monozygotic twinning rate was 1.97%, without a significant difference between D5/6 and D3 embryos in frozen cycles (1.95% vs. 1.56%, p = 0.55). IVF and ICSI were associated with a lower incidence of MCDA twins than observed in the PGT group (IVF: adjusted odds ratio [aOR] = 0.40, p = 0.009; ICSI: aOR = 0.38, p = 0.011). The incidence rates of specific severe complications in MCDA twins, such as twin‒twin transfusion syndrome, selective intrauterine growth restriction, and twin anemia pol

Abstract

This study aimed to explore the associations between assisted reproductive technology (ART) modality and chorionicity in monozygotic twinning pregnancies following single blastocyst frozen-thawed embryo transfer. This retrospective cohort study analyzed 30,121 single embryo transfer cycles from January 2013 to December 2022 but focused on 251 monozygotic twinning pregnancies following single blastocyst frozen-thawed embryo transfer, including 144 monochorionic diamniotic (MCDA) twins and 107 dichorionic diamniotic (DCDA) twins. Regression analysis was performed to determine the risk factors for the subtypes of monozygotic twinning pregnancies after ART. Pregnancy complications and neonatal outcomes of the MCDA and DCDA groups were compared, and subgroup analyses among the in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and preimplantation genetic testing (PGT) groups were performed. The overall monozygotic twinning rate was 1.97%, without a significant difference between D5/6 and D3 embryos in frozen cycles (1.95% vs. 1.56%, p = 0.55). IVF and ICSI were associated with a lower incidence of MCDA twins than observed in the PGT group (IVF: adjusted odds ratio [aOR] = 0.40, p = 0.009; ICSI: aOR = 0.38, p = 0.011). The incidence rates of specific severe complications in MCDA twins, such as twin‒twin transfusion syndrome, selective intrauterine growth restriction, and twin anemia polycythemia sequence, were 2.78%, 2.78%, and 0.69%, respectively. No significant differences were observed in other adverse pregnancy or neonatal outcomes among the MCDA, DCDA, and ART modalities. PGT may be associated with an increased incidence of MCDA twins following single blastocyst frozen-thawed embryo transfer. The incidence of specific maternal-fetal complications for MCDA twins, such as twin‒twin transfusion syndrome and selective intrauterine growth restriction, remains noteworthy. However, the occurrence rates of other adverse pregnancy complications and neonatal outcomes of MCDA twins and DCDA twins are comparable.

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