Problem: The COVID‐19 pandemic has many clinical manifestations. Rapid vaccine development raised concerns and speculations about future fertility outcomes and vaccine safety. We evaluated the effect of Pfizer‐BioNTech mRNA SARS‐CoV‐2 vaccine on IVF treatment, oocyte and embryo quality, and pregnancy outcomes.Method of study: This prospective, observational cohort study was conducted in a referral IVF Unit, 3/2021‐5/2021. We aimed to recruit all women undergoing IVF/ICSI cycles from 3/1–4/30/2021, 2‐8 weeks after the second vaccination, and to analyze 50–60 samples in the 2‐month period. Patients were categorized according to serum antibody levels: positive for spike (S), positive for nucleotide (N), or negative for both. On the day of ovum pick‐up, follicular fluid and blood samples were analyzed for anti‐nucleotide (anti‐N) antibodies, and anti‐spike (anti‐S) antibodies, hormonal profile, C‐reactive protein (CRP) and other metabolic parameters.Results: Of 59 women enrolled, 37 reported being vaccinated and 22 were not. We found 97% correlation between anti‐S and anti‐N in the blood and the follicular fluid. Follicular fluid was analyzed based on antibody categorization. All IVF treatment parameters in the follicular fluids and serum were comparable, except CRP was significantly elevated among patients with anti‐N antibodies (2.29 [1.42–6.08] vs. 4.11 [1.62–5.75] vs. 1.44 [.36–8.33]; p < .001). Pregnancy outcomes were comparable (44% vs. 33% vs. 50%; p = .97).Conclusion: mRNA SARS‐CoV‐2 vaccine did not appear to affect treatment outcomes or ovarian reserves in the subsequent IVF cycle.

This study evaluated which endometrial preparation protocol in frozen embryo transfer (FET) cycles provides the best results for polycystic ovarian syndrome (PCOS) patients and the general population. This retrospective study of 634 FET cycles was conducted 2016–2018. Cycles were divided into Group A: Artificial endometrial preparations for FET (aFET; n = 348), Group B: Ovulatory cycle (n = 286) to compare two methods of endometrial preparation for FET. Artificial endometrial preparation with exogenous estrogen and progesterone versus natural ovulation cycles, modified natural cycles using hCG for the final triggering and letrozole-induced ovulation with hCG. Anovulatory patients were analyzed separately. Anovulatory PCOS patients had significantly higher pregnancy rates with letrozole treatment compared with aFET cycles (44% vs. 22.5%; p = 0.044). For the entire cohort, ovulatory cycles and aFET were similar in terms of patient characteristics, demographics, infertility causes, treatment protocols and number of embryos transferred. Although the mean ESHRE score of the transferred embryos was higher in the aFET group, we found higher clinical pregnancy rate in the ovulatory cycle FET (41.3% vs. 27.3%, p < 0.0001). A better pregnancy rate was found after ovulatory cycle FET. In the ovulatory cycles, the outcome of letrozole-induced and non-induced cycles were comparable. PCOS patients, as well as the general population, may benefit from ovulation induced FET cycles, with significantly better outcomes in FET in ovulatory cycles.

This prospective, observational study investigated the incidence of irregular cleavage (IRC) among human embryos and its influence on IVF treatment outcomes. It included 1001 women who underwent 1976 assisted reproduction treatments during 2016–2021 in a single IVF clinic. Embryo morphokinetics were analyzed and evaluated for the association between IRC and women’s characteristics, treatment characteristics, and pregnancy outcomes. The incidence of IRC was 17.5% (1689/9632 embryos). Of these, 85% of the embryos had one IRC, 15% had multiple IRC and 35% of IRC events occurred during the embryo’s first cell cycle. IRC embryos were found to correlate with male factor (p = 0.01) and higher ICSI rate (p = 0.01). Age, BMI, parity, basal FSH level, stimulation protocol, and number of retrieved oocytes did not differ between groups. Embryos with early IRC or more than one IRC had lower blastulation rates (p = 0.01 for each). Fresh cycles with IRC embryos had a lower clinical pregnancy rate (p = 0.01) and embryos with early IRC had a lower live birth rate (p = 0.04) compared to embryos without IRC. Frozen transfer cycles of blastocyst embryos, with or without IRC, had comparable results. In conclusion, the number of abnormal cleavage events and their timing are important factors in the prognosis of the developing human embryo.