Expert consensus on the morphological evaluation of human cleavage-stage embryos and blastocysts

SARS-CoV-2 infection, vaccination and in vitro fertilization treatment: A prospective cohort study

BACKGROUND

The impact of COVID-19 on reproductive health is controversial. The association between female SARS-CoV-2 infection and laboratory and pregnancy outcomes following subsequent in vitro fertilization (IVF) treatment remains unclear. This study aimed to investigate the relationship between IVF treatment at different time intervals after SARS-CoV-2 infection and reproductive outcomes.

METHODS

A prospective cohort study of 920 IVF cycles post-SARS-CoV-2 infection was conducted. Modified Poisson regression and logistic regression models were utilized to evaluate oocyte- and embryo-related outcomes as well as clinical outcomes. Stratified analyses were also performed based on the vaccination status of the female participants.

RESULTS

SARS-CoV-2 infection within three months was associated with reduced available [Adjusted RR (aRR): 0.96, 95 %CI: 0.91-1.00] and top-quality embryos (aRR: 0.90, 95 %CI: 0.83-0.98) in subsequent IVF treatment. Among patients failing to finish the three-dose vaccination, the interval between SARS-CoV-2 infection and cycle initiation of less than 90 days was associated with a lower number of oocytes retrieval (aRR: 8.81, 95 %CI: 8.24-9.41 vs aRR: 9.64, 95 %CI: 9.06-10.25), available embryos (aRR: 0.93, 95 %CI: 0.88-0.99), and top-quality embryos (aRR: 0.81, 95 %CI: 0.72-0.91) rather than among fully vaccinated women. Moreover, COVID-19 infection was not associated with biochemical pregnancy, clinical pregnancy, embryo implantation, and early abortion either in fresh embryo transfer (ET) or frozen ET.

CONCLUSIONS

This study indicated that initiating IVF treatment within 90 days of SARS-CoV-2 infection might reduce the likelihood of obtaining available and top-quality embryos, especially among those who had not completed the three-dose vaccination. Nevertheless, female COVID-19 infection did not affect pregnancy or early abortion. Further rigorously designed studies are required to support these findings.

Association of fat distribution differences in infertile women with assisted reproductive outcomes: A prospective cohort study

OBJECTIVE

To investigate the impacts of fat distribution on assisted reproductive outcomes in infertile women.

METHODS

The study randomly recruited 576 infertile women who underwent assisted reproductive technology treatment at the Reproductive Medicine Center of the First Affiliated Hospital of Anhui Medical University between July and October 2022. Questionnaires and body composition measurements were administered to assess baseline information and fat distribution. The numbers of oocytes, zygotes presenting with two pronuclei (2PN), and available embryos were tracked at the end of the cycle. Multifactorial logistic regression models and restricted cubic spline (RCS) curve models were used to explore the relationships between fat distribution and reproductive outcomes while controlling for confounding factors.

RESULTS

The study found that the participants had a mean age of 30.82 years. The analysis showed that there was a significant difference between the amount of leg body fat mass (LBFM) and the distribution of reproductive outcomes. However, there was no significant correlation between the level of visceral fat and reproductive outcomes. After taking confounding factors into account, the multifactorial regression analysis showed that the total body fat mass and the number of oocytes (odds ratio (OR) 0.92, 95% confidence interval (CI) 0.84-0.99), 2PN (OR 0.92, 95% CI 0.84-0.99), and embryos available for transfer (OR 0.90, 95% CI 0.82-0.99) were negatively correlated. RCS modeling revealed a linear dose-response relationship between LBFM and assisted reproductive outcomes.

CONCLUSION

Fat distribution varies among infertile women, and higher amounts of fat are associated with poorer assisted reproductive outcomes.