The relationship between blastocyst morphology and the sex ratio of singleton births in single blastocyst transfer cycles: A retrospective cohort study
medRxiv (Cold Spring Harbor Laboratory)(2022)
Abstract
Background To study the relationship between blastocyst morphology and the sex ratio of singleton births in single blastocyst transfer cylces.
Methods This retrospective cohort study included women who underwent in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) from January 2017 to December 2019 and obtained a single live baby following a single blastocyst transfer. The sex ratio which influenced by many possible factors were studied. Age-stratified analysis was performed for the maternal and paternal groups younger and older than 35 years. The 3108 cycles included here were grouped by sex at birth (male: 1777 cycles and female: 1331 cycles). Blastocysts were conceived via 2834 IVF and 274 ICSI treatments, and were used for 1054 fresh ET cycles and 2054 frozen-thawed embryo transfer (FET) cycles.
Results Sex ratio among singleton of poor blastocyst decreased significantly compared to those of good blastocyst (51.5% vs 60%, P <0.001). The results of multivariate logistic analysis showed that high-quality blastocysts had a 151% higher probability of being male singleton than poor-quality blastocysts ( P <0.001). Further stratified analysis shows that in both group younger than 35 the sex ratio increased significantly in grades A and/or B trophectoderm ( P <0.001) and good-quality blastocysts ( P <0.001). While grade A inner cell mass (ICM) degree was significantly associated with a lower sex ratio than grade B ( P <0.05).
Conclusions A single high-quality blastocyst transfer was significantly associated with a higher neonatal sex ratio. Grade A trophectoderm and grade B ICM contributed to improving the implantation potential of male blastocysts, especially in infertile men or women ≤35 years old.
### Competing Interest Statement
The authors have declared no competing interest.
### Funding Statement
NO
### Author Declarations
I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.
Yes
The details of the IRB/oversight body that provided approval or exemption for the research described are given below:
The study was carried out after the protocol was approved by the Institutional Review Board of The Third Affiliated Hospital of Zhengzhou University. Informed consent was waived due to retrospective design of the study based on our local ethics committee protocols.
I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.
Yes
I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).
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I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.
Yes
within the manuscript and/or Supporting Information files
* (IVF)
: in vitro fertilization
(ICSI-ET)
: intracytoplasmic sperm injection-embryo transfer
(FET)
: frozen-thawed embryo transfer
(PSR)
: primary sex ratio
(SSR)
: secondary sex ratio
(SBT)
: single blastocyst transfer
(ICM)
: inner cell mass
(TE)
: trophectoderm
(ART)
: assisted reproductive technologies
(PGT)
: preimplantation genetic testing
(BMI)
: body mass index
(DMSO)
: dimethyl sulfoxide
(OHSS)
: ovarian hyperstimulation syndrome
(HCG)
: human chorionic gonadotropin
(HRT)
: hormone replacement therapy
(SPSS)
: Statistical Package for Social Sciences
MoreTranslated text
Key words
singleton blastocyst transfer cycles,blastocyst morphology,singleton births,sex ratio,cohort study
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