ArticleReproductive biology and endocrinology : RB&E2019
The risk of secondary sex ratio imbalance and increased monozygotic twinning after blastocyst transfer: data from the Japan Environment and Children's Study.
Article in Reproductive biology and endocrinology : RB&E, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers, 2 of them syntheses that pooled it.
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Who cites it
13 citing papers in PubMed, 2 syntheses or guidelines pooled it, 31 citations in OpenAlex.
- New insights into the (epi)genetics of twinning.Human reproduction (Oxford, England) · 2024Pooled it
- Congenital anomaly and perinatal outcome following blastocyst- vs cleavage-stage embryo transfer: systematic review and network meta-analysis.Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology · 2023Pooled it
- Clinical outcomes of dichorionic diamniotic twin pregnancies following single versus double embryo transfer in human medically assisted reproduction.Human reproduction (Oxford, England) · 2026Article
- The Effect of Assisted Reproductive Technologies on Human Sex Ratios.The Australian & New Zealand journal of obstetrics & gynaecology · 2025Article
- Effects of Various Transfer Strategies of Frozen-Thawed Cleavage-Stage and Blastocyst Embryos on Pregnancy and Neonatal Outcomes in Different Age Groups.Journal of multidisciplinary healthcare · 2025Article
- Pregnancy incidence and associated risk factors of dichorionic triamniotic triplet under assisted reproduction: A large sample of clinical data analysis.Frontiers in endocrinology · 2023Article
- Blastocyst versus cleavage transfers: who benefits?Archives of gynecology and obstetrics · 2022Article
- Placental Abnormalities are Associated With Specific Windows of Embryo Culture in a Mouse Model.Frontiers in cell and developmental biology · 2022Article
- On the origin of zygosity and chorionicity in twinning: evidence from human in vitro fertilization.Journal of assisted reproduction and genetics · 2021Review
- Serum 25-Hydroxyvitamin D Concentrations and Atopic Dermatitis in Early Childhood: Findings from the Japan Environment and Children's Study.Nutrients · 2021Article
- Article
- Does the sex ratio of singleton births after frozen single blastocyst transfer differ in relation to blastocyst development?Reproductive biology and endocrinology : RB&E · 2020Article
- Perinatal outcome in children born after assisted reproductive technologies.Upsala journal of medical sciences · 2020Review
Corrections and comments
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Authors and funding
20 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundSome studies have suggested that blastocyst transfer is associated with i) imbalance in the secondary sex ratio (SSR) (which favors male offspring), ii) increased incidence of monozygotic twins (MZT). In contrast, others have not found these changes. In this study, we evaluated the association between blastocyst transfer and SSR and MZT, considering potential parental confounders.
methodsThe Japan Environment and Children's Study is a large, nationwide longitudinal birth cohort study funded by the Ministry of the Environment of Japan. We used this large dataset, including 103,099 pregnancies, to further investigate the association between blastocyst transfer, SSR and MZT, using spontaneously conceived pregnancies, non-assisted reproductive technology (non-ART) treatment (intrauterine insemination and ovulation induction with timed intercourse) and cleavage stage embryo transfer for comparison. We evaluated the association with each group, the SSR, and the frequency of MZT, calculating the adjusted odds ratio (AOR) using multivariable logistic regression analyses, adjusting for potential parental confounders such as basic health and socioeconomic status.
resultsFor each group (spontaneous conception vs. non-ART treatment vs. cleavage stage embryo transfer vs. blastocyst transfer), the percentages of males were 51.3% vs 50.7% vs 48.9% vs 53.4% and the monozygotic twinning rates per pregnancy were 0.27% vs 0.11% vs 0.27% vs 0.99% respectively. Multivariate logistic regression analyses indicated that blastocyst transfer was significantly associated with a higher SSR and higher incidence of MZT than the other three groups (SSR: AOR 1.095, 95% CI1.001-1.198; MZT: AOR 4.229, 95% CI 2.614-6.684).
conclusionsThere are significant relationships between blastocyst transfer and SSR imbalance and a higher occurrence of MZT.
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Registered trials
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