The impact of past COVID-19 infection on pregnancy rates in frozen embryo transfer cycles

Assisted Reproductive Technology During COVID-19: A Population-Based Study Of Pregnancy Outcomes

We assessed the impact of the COVID-19 pandemic on the pregnancy outcomes of patients who used assisted reproductive technology. We conducted a population-based cohort study of 443,101 patients who conceived naturally or with assisted reproductive technology between December 2015 and July 2021 and had a delivery in hospitals of Quebec, Canada. The main exposure measure was use of assisted reproductive technology before or during the pandemic. Outcomes included preeclampsia, preterm birth, and other pregnancy complications. We used adjusted log-binomial regression models to estimate risk ratios (RR) and 95% confidence intervals (CI) for the association of assisted reproductive technology with adverse pregnancy outcomes compared with natural conception before vs. during the pandemic. In secondary analyses, we examined the association of COVID-19 infection with pregnancy outcomes among women who used assisted reproductive technology. Compared with natural conception, assisted reproductive technology was associated with an increased risk of preeclampsia (RR 1.43; 95% CI 1.21-1.68), preterm birth (RR 2.07; 95% CI 1.84-2.33), and low birth weight (RR 1.94; 95% CI 1.72-2.20) during the pandemic. However, the same risks were also present before the pandemic. Compared with no infection, COVID-19 infection was not associated with adverse outcomes among women who conceived with assisted reproductive technology. This study suggests that the COVID-19 pandemic did not significantly impact the pregnancy outcomes of women who underwent assisted reproductive procedures in Quebec. The findings are reassuring for patients concerned about the potential reproductive effects of the pandemic.

Influence of COVID-19 infection on early pregnancy outcomes in different periods around frozen embryo transfer

PURPOSE

The study aimed to investigate the potential influence of COVID-19 infection on embryo implantation and early development in women undergoing frozen embryo transfer (FET), with a specific focus on infections occurring at different periods around FET.

METHODS

A retrospective analysis was performed on women who had undergone FET during a period marked by a significant surge in COVID-19 infection in Shanghai. All enrolled women experienced their first documented COVID-19 infection around the time of FET, ensuring that infections did not occur prior to oocyte retrieval. Participants were categorized into six groups based on the timing of infection: uninfected, ≥ 60 days, < 60 days before FET, 0-14 days, 15-28 days, and 29-70 days after FET. Clinical outcomes were compared across these groups.

RESULTS

The infection rate among the total of 709 cases was 78.28%. Infected individuals exhibited either asymptomatic or mild symptoms. The ongoing pregnancy rates for the first four groups were 40.7%, 44.4%, 40.5%, and 34.2% (P = 0.709) respectively, biochemical pregnancy rates (59.1% vs. 61.1% vs. 67.6% vs. 55.7%, P = 0.471) and clinical pregnancy rates (49.6% vs. 55.6% vs. 55.4% vs. 48.1%, P = 0.749), all showed no significant differences. Early spontaneous abortion rates across all six groups were 18.3%, 20.0%, 25.0%, 28.9%, 5.4%, and 19.0% respectively, with no significant differences (P = 0.113). Multivariable logistic analysis revealed no significant correlation between the infection and ongoing pregnancy.

CONCLUSION

Asymptomatic or mild COVID-19 infections occurring around FET do not appear to have a significant adverse impact on early pregnancy outcomes.

Mediterranean diet improves blastocyst formation in women previously infected COVID-19: a prospective cohort study

Objectives

Our study tries to investigate the effect of the Mediterranean diet (MeDiet) on assisted reproductive treatment outcomes in women after COVID-19 infection.

Design

A prospective observational cohort study in the Reproductive and Genetic Hospital of CITIC-Xiangya from February 2023 to August 2023.Subjects: A total of 605 participants previously infected with COVID-19 were enrolled.

Exposure

None.

Main outcome measurement

The primary outcomes are oocyte and embryo quality. The secondary outcomes are pregnancy outcomes.

Results

A majority of participants (n = 517) followed low to moderate MeDiet, and only a small group of them (n = 88) followed high MeDiet. The blastocyst formation rate is significantly higher in MeDiet scored 8-14 points women (46.08%), compared to the other two groups (which is 41.75% in the low adherence population and 40.07% in the moderate adherence population respectively) (p = 0.044). However, the follicle number on hCG day, yield oocytes, normal fertilized zygotes, fertilization rate, day three embryos (cleavage embryos), and embryo quality are comparable among the three groups. For those who received embryo transfer, we noticed an obvious trend that with the higher MeDiet score, the higher clinical pregnancy rate (62.37% vs. 76.09% vs. 81.25%, p = 0.197), implantation rate (55.84% vs. 66.44% vs. 69.23%, p = 0.240) and ongoing pregnancy rate (61.22% vs. 75.00% vs. 81.25%, p = 0.152) even though the p values are not significant. An enlarging sample size study, especially in a high adherence population should be designed to further verify the effects of MeDiet's role in improving IVF performance.

Conclusion

High adherence to MeDiet is associated with improved blastocyst formation in women after COVID-19 infection. There is also a trend that high adherence to MeDiet might be beneficial to clinical pregnancy, embryo implantation as well as ongoing pregnancy in these women.

The type of COVID-19 vaccination does not affect reproductive function and pregnancy outcomes in infertile couples

Introduction

Studies on the effect of vaccine type and two other vaccines other than inactivated vaccines approved in China on in vitro fertilization (IVF) pregnancy outcomes are rare. To complement and confirm the existing findings, this research aimed to investigate whether there are adverse effects of different vaccine types in females and males on reproductive function and clinical pregnancy.

Methods

This retrospective study enrolled 6,455 fresh embryo transfer cycles at the First Affiliated Hospital of Zhengzhou University between May 1, 2021, and October 31, 2022. The primary outcome is the clinical pregnancy rate (CPR). At the same time, the secondary results are the number of oocytes retrieved, two pronuclei (2PN) rate, blastocyst formation rate, high-quality blastocyst rate, and semen parameters (volume, density, sperm count, forward motility rate, total motility rate, immobility rate, and DNA fragment index (DFI) rate).

Results

In the comparison of ovarian stimulation indicators, no statistically significant differences (P > 0.05) were found in Gn days, endometrial thickness, 2PN rate, metaphase 2 (MII) rate, high-quality embryo rate, and blastocyst formation rate. No significant differences (P>0.05) were found in age, body mass index (BMI), education level, and semen parameters (volume, density, sperm count, forward motility rate, total motility rate, immobility rate, and DFI rate) in these four groups. The multivariate regression model showed that neither the types of vaccines nor the vaccination status of both infertile couples significantly affected clinical pregnancy.

Discussion

The type of vaccine does not appear to have an unfavorable effect on ovarian stimulation, embryo development, semen parameters, and clinical pregnancy.

Effects of SARS-COV-2 infection during the frozen-thawed embryo transfer cycle on embryo implantation and pregnancy outcomes

STUDY QUESTION

Does severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during the frozen-thawed embryo transfer (FET) cycle affect embryo implantation and pregnancy rates?

SUMMARY ANSWER

There is no evidence that SARS-CoV-2 infection of women during the FET cycle negatively affects embryo implantation and pregnancy rates.

WHAT IS KNOWN ALREADY

Coronavirus disease 2019 (COVID-19), as a multi-systemic disease, poses a threat to reproductive health. However, the effects of SARS-CoV-2 infection on embryo implantation and pregnancy following fertility treatments, particularly FET, remain largely unknown.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study, included women who underwent FET cycles between 1 November 2022 and 31 December 2022 at an academic fertility centre.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women who tested positive for SARS-CoV-2 during their FET cycles were included in the COVID-19 group, while those who tested negative during the same study period were included in the non-COVID-19 group. The primary outcome was ongoing pregnancy rate. Secondary outcomes included rates of implantation, biochemical pregnancy, clinical pregnancy, early pregnancy loss, and ongoing pregnancy. Multivariate logistic regression models were applied to adjust for potential confounders including age, body mass index, gravidity, vaccination status, and endometrial preparation regimen. Subgroup analyses were conducted by time of infection with respect to transfer (prior to transfer, 1-7 days after transfer, or 8-14 days after transfer) and by level of fever (no fever, fever <39°C, or fever ≥39°C).

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 243 and 305 women were included in the COVID-19 and non-COVID-19 group, respectively. The rates of biochemical pregnancy (58.8% vs 62.0%, P = 0.46), clinical pregnancy (53.1% vs 54.4%, P = 0.76), implantation (46.4% vs 46.2%, P = 0.95), early pregnancy loss (24.5% vs 26.5%, P = 0.68), and ongoing pregnancy (44.4% vs 45.6%, P = 0.79) were all comparable between groups with or without infection. Results of logistic regression models, both before and after adjustment, revealed no associations between SARS-CoV-2 infection and rates of biochemical pregnancy, clinical pregnancy, early pregnancy loss, or ongoing pregnancy. Moreover, neither the time of infection with respect to transfer (prior to transfer, 1-7 days after transfer, or 8-14 days after transfer) nor the level of fever (no fever, fever <39°C, or fever ≥39°C) was found to be related to pregnancy rates.

LIMITATIONS, REASONS FOR CAUTION

The retrospective nature of the study is subject to possible selection bias. Additionally, although the sample size was relatively large for the COVID-19 group, the sample sizes for certain subgroups were relatively small and lacked adequate power, so these results should be interpreted with caution.

WIDER IMPLICATIONS OF THE FINDINGS

The study findings suggest that SARS-CoV-2 infection during the FET cycle in females does not affect embryo implantation and pregnancy rates including biochemical pregnancy, clinical pregnancy, early pregnancy loss, and ongoing pregnancy, indicating that cycle cancellation due to SARS-CoV-2 infection may not be necessary. Further studies are warranted to verify these findings.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Key Research and Development Program of China (2023YFC2705500, 2019YFA0802604), National Natural Science Foundation of China (82130046, 82101747), Shanghai leading talent program, Innovative research team of high-level local universities in Shanghai (SHSMU-ZLCX20210201, SHSMU-ZLCX20210200, SSMU-ZLCX20180401), Shanghai Jiao Tong University School of Medicine Affiliated Renji Hospital Clinical Research Innovation Cultivation Fund Program (RJPY-DZX-003), Science and Technology Commission of Shanghai Municipality (23Y11901400), Shanghai Sailing Program (21YF1425000), Shanghai's Top Priority Research Center Construction Project (2023ZZ02002), Three-Year Action Plan for Strengthening the Construction of the Public Health System in Shanghai (GWVI-11.1-36), and Shanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant Support (20161413). The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

The association of post-embryo transfer SARS-CoV-2 infection with early pregnancy outcomes in in vitro fertilization: a prospective cohort study

BACKGROUND

The influence of SARS-CoV-2 infection after embryo transfer on early pregnancy outcomes in in vitro fertilization or intracytoplasmic sperm injection-embryo transfer treatment remains inadequately understood. This knowledge gap endures despite an abundance of studies investigating the repercussions of preceding SARS-CoV-2 infection on early pregnancy outcomes in spontaneous pregnancies.

OBJECTIVE

This study aimed to investigate the association between SARS-CoV-2 infection within 10 weeks after embryo transfer and early pregnancy outcomes in patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment.

STUDY DESIGN

This prospective cohort study was conducted at a single public in vitro fertilization center in China. Female patients aged 20 to 39 years, with a body mass index ranging from 18 to 30 kg/m2, undergoing in vitro fertilization/intracytoplasmic sperm injection treatment, were enrolled between September 2022 and December 2022, with follow-up extended until March 2023. The study tracked SARS-CoV-2 infection time (≤14 days, ≤28 days, and ≤10 weeks after embryo transfer), symptoms, vaccination status, the interval between vaccination and embryo transfer, and early pregnancy outcomes, encompassing biochemical pregnancy rate, implantation rate, clinical pregnancy rate, and early miscarriage rate. The study used single-factor analysis and multivariate logistic regression to examine the association between SARS-CoV-2 infection status, along with other relevant factors, and the early pregnancy outcomes.

RESULTS

A total of 857 female patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment were analyzed. In the first stage, SARS-CoV-2 infection within 14 days after embryo transfer did not have a significant negative association with the biochemical pregnancy rate (adjusted odds ratio, 0.74; 95% confidence interval, 0.51-1.09). In the second stage, SARS-CoV-2 infection within 28 days after embryo transfer had no significant association with the implantation rate (36.6% in infected vs 44.0% in uninfected group; P=.181). No statistically significant association was found with the clinical pregnancy rate after adjusting for confounding factors (adjusted odds ratio, 0.69; 95% confidence interval, 0.56-1.09). In the third stage, SARS-CoV-2 infection within 10 weeks after embryo transfer had no significant association with the early miscarriage rate (adjusted odds ratio, 0.77; 95% confidence interval, 0.35-1.71).

CONCLUSION

Our study suggests that SARS-CoV-2 infection within 10 weeks after embryo transfer may not be negatively associated with the biochemical pregnancy rate, implantation rate, clinical pregnancy rate, and early miscarriage rate in patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment. It is important to note that these findings are specific to the target population of in vitro fertilization/intracytoplasmic sperm injection patients aged 20 to 39 years, without previous SARS-CoV-2 infection, and with a body mass index of 18 to 30 kg/m2. This information offers valuable insights, addressing current concerns and providing a clearer understanding of the actual risk associated with SARS-CoV-2 infection after embryo transfer.

Immediate application of frozen-thawed embryo transfer cycle in month following COVID-19 recovery does not impair ongoing pregnancy outcome

OBJECTIVE

To investigate whether immediate frozen-thawed embryo transfer (FET) in the next month following coronavirus disease 2019 (COVID-19) recovery affects ongoing pregnancy outcome.

METHODS

This was a retrospective cohort study carried out at a university-affiliated reproductive medicine center. The study group (post-COVID-19 group) comprised women who were affected by COVID-19 in December 2022 and immediately underwent FET in January 2023 after recovery, with transferred embryos not exposed to the infection. The control group comprised women treated during the pre-COVID-19 period (January 2019). Multivariable logistic regression analysis and a propensity score matching (PSM) approach were used to control potential confounders and selection bias.

RESULTS

A total of 200 women were included in the post-COVID-19 group and 641 women were enrolled in the control group. The rate of ongoing pregnancy was comparable between the study cohorts in both the unadjusted and confounder-adjusted logistic regression models. Other reproductive outcomes, including the odds of a positive pregnancy test, implantation, clinical pregnancy and early pregnancy loss, were similar between the comparison groups. PSM models further confirmed the lack of significant differences in pregnancy outcome between the post-COVID-19 group and the control group.

CONCLUSIONS

Among patients affected by COVID-19 for whom the transferred embryos were generated prior to infection, an immediate FET cycle in the next month after recovery does not seem to compromise ongoing pregnancy outcome. Thus, women who have frozen embryos from preinfection cycles should be counseled and encouraged to undergo FET as soon as possible after COVID-19 recovery. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Impact of COVID-19 convalescence on pregnancy outcomes in patients undergoing IVF/ICSI during fresh ART cycles: a retrospective cohort study

Objective

The aim was to study the impact of coronavirus disease 2019 (COVID-19) convalescence on female fertility and laboratory and clinical outcomes in fresh assisted reproductive technology (ART) cycles.

Methods

In this retrospective cohort study, we analyzed data from 294 patients who had recovered from COVID-19 and who underwent fresh ART cycles between January and March 2023 (COVID-19 group). This group was compared with 631 patients who underwent similar ART cycles in the same period in 2022 but without having been infected with COVID-19 (non-COVID-19 group). The analysis focused on comparison of basic demographic characteristics and laboratory parameters of patients in each group. The primary outcome measure was the clinical pregnancy rate, which was examined to assess the impact of COVID-19 infection on the efficacy of ART treatment.

Results

Basal follicle-stimulating hormone (FSH) levels were significantly lower and antral follicle count (AFC) was markedly higher in the COVID-19 group compared to the non-COVID-19 group (P<0.001 and P=0.004, respectively). The predominant ovarian stimulation protocol in the COVID-19 group was GnRH antagonists (64.85%, P<0.001), with a reduced gonadotropin (Gn) dosage and duration in comparison to the non-COVID-19 group (P<0.05). Although the number of blastocysts formed was lower in the COVID-19 group (P=0.017), this group also exhibited a higher blastocyst freezing rate and a higher rate of high-quality embryos per retrieved oocyte (P<0.001 and P=0.023, respectively). Binary logistic regression analysis indicated that COVID-19 convalescence did not significantly impact clinical pregnancy rates in fresh transfer cycles (odds ratio [OR] = 1.16, 95% confidence interval [CI] = 0.68-1.96, P=0.5874). However, smooth curve-fitting and threshold effect analysis revealed an age-related decline in clinical pregnancy rates in both groups, more pronounced in the COVID-19 group, for women aged over 38 years, with the likelihood of clinical pregnancy decreasing by 53% with each additional year of age (odds ratio [OR] = 0.81, 95% confidence interval [CI] = 0.61-1.08, P=0.1460; odds ratio [OR] = 0.47, 95% CI = 0.21-1.05, P=0.0647).

Conclusions

Our findings present no substantial evidence of adverse effects on clinical pregnancy outcomes in fresh ART cycles in patients undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) during the period of convalescence from COVID-19. However, age emerges as a significant factor influencing these outcomes. Notably, for women above 38 years of age, the likelihood of clinical pregnancy in patients with a prior COVID-19 infection decreased by 53% with each additional year. This highlights the importance of considering maternal age, especially in the context of COVID-19, when evaluating the likelihood of successful pregnancy following ART treatments.

Does SARS Cov-2 infection affect the IVF outcome - A systematic review and meta-analysis

STUDY QUESTION

What is the effect of SARS Cov-2 on IVF outcome?

SUMMARY ANSWER

Mild or asymptomatic Covid-19 infection does not appear to affect clinical or ongoing pregnancy rate after IVF.

WHAT IS ALREADY KNOWN

Covid-19 has been shown to affect female and male fertility and reproductive function. Studies have shown variable results regarding impact of Covid-19 on IVF outcome with few reporting impaired ovarian reserve, oocyte and embryo quality, semen parameters, clinical pregnancy rate (CPR) and live birth rate (LBR) while others reported no effect on IVF outcome.

STUDY DESIGN, SIZE, DURATION

An electronic database search of PubMed, EMBASE, SCOPUS, WHO Covid-19 database, Clinical trials.gov and Cochrane Central was performed for articles published in English language between 1st January 2020 and 15th October 2022 by two independent reviewers using predefined eligibility criteria We have included observational studies both prospective and retrospective, cohort studies, and case control studies and excluded narrative reviews, case studies, cost-effectiveness studies or diagnostic studies. Risk of bias was assessed using NOS and quality of evidence was graded by GRADE pro.

PARTICIPANTS, SETTINGS, METHODS

Studies comparing women undergoing IVF and comparing Covid-19 affected with those unaffected by Covid-19 were included. Also, studies comparing immune group (infected or vaccinated) in the study group and unaffected as controls (historical controls, IVF cycles done prior to Covid-19 outbreak but matched with study group) were included. Those with no comparison group or published in language other than English language or duplicate studies were excluded.

MAIN RESULTS AND ROLE OF CHANCE

We identified 5046 records and after full text screening of 82 studies, 12 studies were selected for final review. For the clinical pregnancy rate, there was no difference in the CPR in covid recovered or control patients (OR 0.90, 95 % CI = 0.67 to1.21; I2 = 29 %). Similarly, there was no significant effect on implantation rate (RR 0.92, 95 % CI = 0.68 to1.23; I2 = 31 %) and ongoing pregnancy rate (RR 0.96, 95 % CI = 0.79 to 1.15;I2 = 21 %). The mean number of the oocyte retrieved per patient was not significantly different in both the groups (mean difference 0.52, 95 % CI = -1.45 to 2.49; I2 = 75 %). The certainty of the evidence was low.

LIMITATIONS

The meta-analysis is based on observational studies each involving small number of participants. Few studies reported outcomes as per patient while others reported as per cycle, for uniformity we have reported outcomes as per cycle. Sample size in most of studies was small.

WIDER IMPLICATIONS OF FINDINGS

This systematic review has not shown any significant effect on the outcome of IVF cycles in patients post Covid-19 recovery compared to controls. But given the sample size, the findings should be considered with caution.

REGISTRATION

The review protocol has been registered on PROSPERO (registration number CRD42022314515).

Pregnancy outcomes after frozen-thawed embryo transfer in women with COVID-19 history: A prospective cohort study

The clinical effect of Coronavirus disease 2019 (COVID-19) on endometrial receptivity and embryo implantation remains unclear. Herein, we aim to investigate whether a COVID-19 history adversely affect female pregnancy outcomes after frozen-thawed embryo transfer (FET). This prospective cohort study enrolled 230 women who underwent FET cycles from December 2022 to April 2023 in an academic fertility center. Based on the history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection before FET, women were divided into the infected group (n = 136) and the control group (n = 94). The primary outcome was the clinical pregnancy rate per cycle. Multivariate logistic regression analysis was conducted to adjust for potential confounders, while subgroup analysis and restricted cubic splines were used to depict the effect of postinfection time interval on FET. The results showed that the clinical pregnancy rate was 59.6% in the infected group and 63.9% in the control group (p = 0.513). Similarly, the two groups were comparable in the rates of biochemical pregnancy (69.1% vs. 76.6%; p = 0.214) and embryo implantation (51.7% vs. 54.5%; p = 0.628). After adjustment, the nonsignificant association remained between prior infection and clinical pregnancy (OR = 0.78, 95% CI: 0.42-1.46). However, the odds for clinical pregnancy were significantly lower in the ≤30 days subgroup (OR = 0.15, 95% CI: 0.03-0.77), while no statistical significance was detected for 31-60 days and >60 days subgroups compared with the uninfected women. In conclusion, our findings suggested that SARS-CoV-2 infection in women had no significant effect on subsequent FET treatment overall, but pregnancy rates tended to be decreased if vitrified-thawed embryos were transferred within 30 days after infection. A 1-month postponement should be rationally recommended, while further studies with larger sample groups and longer follow-up periods are warranted for confirmation.

Effects of SARS-CoV-2 infection on embryological outcomes in assisted reproductive technology during the Omicron epidemic

BACKGROUND

The influence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on assisted reproductive technology (ART) has received increasing attention. It has been reported that the SARS-CoV-2 RiboNucleic Acid (RNA) cannot be detected in follicular fluid and granulosa cells. However, the detection rate of SARS-CoV-2 RNA in immature oocytes and blastocysts has still unknown. Moreover, the effect of SARS-CoV-2 infection on embryological outcomes in ART during the Omicron epidemic is limited.

METHODS

A prospective study was performed to explore the detection rate of viral RNA in biological specimens from patients who tested positive for SARS-CoV-2 RNA and the effects of SARS-CoV-2 infection on embryological outcomes. A total of 211 patients underwent transvaginal oocyte retrieval at the Third Affiliated Hospital of Guangzhou Medical University between December 13, 2022 and December 30, 2022. Prior to transvaginal oocyte retrieval, 61 individuals tested positive for SARS-CoV-2 RNA within 24 h. Follicular fluid was preserved during oocyte retrieval. Granular cells were collected after degranulation (Intracytoplasmic sperm injection only). Immature oocytes were collected at the end of the ICSI. Unavailable blastocysts were collected on day 6 (D6). The TIANLONG SARS-CoV-2 RT-PCR-Kit was used to detect SARS-CoV-2 RNA in all samples. The COVID-19 and Non COVID-19 groups were contrasted in the following areas: fertilization rate, 2PN rate, Day 3 (D3) available embryos rate, D3 good-quality embryos rate, blastocyst formation rate, good-quality blastocyst formation rate.

RESULTS

All samples were negative except for an immature oocytes sample that was positive for SARS-CoV-2 viral RNA with a detection rate of 6.67%. Whether in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), the rate of fertilization, 2PN, D3 available embryos, D3 good-quality embryos, blastocyst formation, good-quality blastocyst formation was not significantly negative different between the COVID-19 and the Non COVID-19 groups. Our findings were validated by an overview of the embryological outcome from the cycles before SARS- Cov-2 infection from the same patient.

CONCLUSIONS

Except for immature oocytes, none of the follicular fluid, granulosa cells, or blastocysts samples contained viral RNA. In addition, SARS-CoV-2 infection had no detrimental effects on the embryological outcomes of ART.

Impact of SARS-CoV-2 infection on clinical outcomes of in vitro fertilization treatments: a systematic review and meta-analysis

The influence of SARS-CoV-2 infection on clinical outcomes in patients undergoing in vitro fertilization has been uncertain. Therefore, this systematic review and meta-analysis aimed to evaluate the impact of past SARS-CoV-2 infection on IVF outcomes. A comprehensive search of PubMed, EMBASE, and Cochrane Library databases was conducted from December 2019 to January 2023. Included studies comparing IVF outcomes between patients with prior SARS-CoV-2 infection and controls without previous infection were analyzed. Study quality was assessed using the Newcastle-Ottawa Quality Assessment Scale. Sensitivity analysis, publication bias, and heterogeneity were also examined. The review protocol was registered with PROSPERO (CRD42023392007). A total of eight studies, involving 317 patients with past SARS-CoV-2 infection and 904 controls, met the inclusion criteria. The meta-analysis revealed no significant differences between the infection group and controls in terms of clinical pregnancy rate (OR 0.97, 95% CI 0.73-1.29; P = 0.82), implantation rate (OR 0.99, 95% CI 0.67-1.46; P = 0.96), or miscarriage rate (OR 0.64, 95% CI 0.15-2.65; P = 0.53). Subgroup analyses based on transfer type demonstrated comparable clinical pregnancy rates between the two groups in both fresh embryo transfer (OR 0.97, 95% CI 0.69-1.36; P = 0.86) and frozen embryo transfer (OR 0.96, 95% CI 0.38-2.44; P = 0.94). In conclusion, this meta-analysis suggests that previous SARS-CoV-2 infection does not have a detrimental impact on clinical outcomes in IVF patients. These findings provide valuable insights into assessing the influence of prior SARS-CoV-2 infection on successful pregnancy outcomes in IVF treatment. The systematic review was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. This review was prospectively registered with the International Prospective Register of Systematic Reviews (ID CRD42023392007) on January 16, 2023.

COVID-19 infection after oocyte retrieval did not have detrimental effects on embryo implantation for frozen embryo transfer

Patients preparing for their renewal fertility treatments with embryos frozen before coronavirus disease 2019 (COVID-19) infection do not need to be concerned about the potential impact of COVID-19 infection on oocyte quality and embryonic development. However, many women are still hesitant to undergo frozen embryo transfer (FET) due to fear of the detrimental effect of COVID-19 infection on endometrial receptivity and embryo implantation. The objective was to explore whether COVID-19 infection after oocyte retrieval is related to an increased risk of adverse pregnancy outcomes in a cohort of Chinese women undergoing FET. A retrospective cohort study was conducted among 300 infertile women undergoing FET with embryos frozen before COVID-19 infection. Women were categorized into noninfection, infection before FET, or infection after FET groups. Multivariable logistic regression was performed to assess the association of COVID-19 infection with clinical pregnancy outcomes, including biochemical pregnancy, clinical pregnancy, and early miscarriage. The implantation rates for patients in the group with infection before FET (29.14%) and the group with infection after FET (30.38%) were not significantly lower than those in the noninfection group (31.03%). The rate of biochemical pregnancy (54.55% vs. 52.27%, p = 0.750; 43.14% vs. 52.27%, p = 0.209) was not significantly different among the three groups. Although the clinical pregnancy rate showed a declining trend from 45.45% in the noninfection group to 38.27% in the group with infection after FET, this result was not statistically significant. The early miscarriage rate was similar in the group with infection before FET and the group with infection after FET compared with that in the noninfection group (3.64% vs. 5.68%, p = 0.496; 6.86% vs. 5.68%, p = 0.739). After adjusting for potential confounders, the biochemical pregnancy rate, clinical pregnancy rate, and early miscarriage rate were not significantly different for patients with infection before or after FET compared with patients without infection. This research indicated that COVID-19 infection after oocyte retrieval with embryos frozen before infection did not cause any detrimental effect on endometrial receptivity for embryo implantation.

Association of SARS-CoV-2 Infection During Controlled Ovarian Stimulation With Oocyte- and Embryo-Related Outcomes

Importance

SARS-CoV-2 infection has had significant effects on the health of people worldwide. Whether SARS-CoV-2 infection during controlled ovarian stimulation (COS) is associated with laboratory outcomes in assisted reproductive technology remains unclear.

Objective

To investigate the association between SARS-CoV-2 infection during COS with oocyte- and embryo-related outcomes.

Design, Setting, and Participants

A multicenter cohort study was conducted of couples undergoing assisted reproductive technology treatments in 7 reproductive centers in 4 provinces in China from October 1, 2022, to December 31, 2022. All couples received nucleic acid testing for SARS-CoV-2 during COS. The SARS-CoV-2-positive group included couples in which either partner was infected with SARS-CoV-2. The SARS-CoV-2-negative group comprised couples without infection.

Exposure

In the SARS-CoV-2-positive group, either partner was infected with SARS-CoV-2 during COS, defined as a positive test result for the SARS-CoV-2 antigen.

Main Outcomes and Measures

Primary outcomes were the available embryo and blastocyst and top-quality embryo and blastocyst rates. Secondary outcomes were the number of oocytes retrieved, the mature oocyte rate, normal fertilization (2 pronuclei observed on day 1 after insemination [2PN]), oocyte degeneration, 2PN cleavage, and blastocyst formation rates.

Results

A total of 585 heterosexual couples with infertility participated in the study (median [IQR] age for female partners, 33 [30-37] years), with 135 couples in the SARS-CoV-2-positive group and 450 in the SARS-CoV-2-negative group. The characteristics of the groups were similar. The SARS-CoV-2-positive group had a significantly lower top-quality embryo rate (odds ratio [OR], 0.83; 95% CI, 0.71-0.96), top-quality blastocyst rate (OR, 0.59; 95% CI, 0.45-0.77), available blastocyst rate (OR, 0.70; 95% CI, 0.59-0.82), and blastocyst formation rate (OR, 0.61; 95% CI, 0.52-0.71) than the SARS-CoV-2-negative group. Analysis of the associations of infection by sex showed that the female positive group had impaired oocyte and embryo quality regarding mature oocyte rate, 2PN cleavage rate, top-quality embryo rate, blastocyst formation rate, available blastocyst rate, and top-quality blastocyst rate compared with the SARS-CoV-2-negative group. Compared with the SARS-CoV-2-negative group, the male positive group and the group of couples with both positive partners had significantly decreased available blastocyst rate, top-quality blastocyst rate, and blastocyst formation rate compared with the SARS-CoV-2 negative group.

Conclusions and Relevance

In this cohort study, SARS-CoV-2 infection during COS was negatively associated with embryo and blastocyst quality. Reproductive physicians should be more attentive to patients with SARS-CoV-2 infection during COS and should give couples who have been infected adequate counseling.

SARS-CoV-2, fertility and assisted reproduction

BACKGROUND

In 2020, SARS-CoV-2 and the COVID-19 pandemic had a huge impact on the access to and provision of ART treatments. Gradually, knowledge of the virus and its transmission has become available, allowing ART activities to resume. Still, questions on the impact of the virus on human gametes and fertility remain.

OBJECTIVE AND RATIONALE

This article summarizes published data, aiming to clarify the impact of SARS-CoV-2 and the COVID-19 disease on human fertility and assisted reproduction, as well as the impact of vaccination, and from this, provide answers to questions that are relevant for people contemplating pregnancy and for health care professionals.

SEARCH METHODS

PUBMED/MEDLINE and the WHO COVID-19 database were searched from inception to 5 October 2022 with search terms focusing on 'SARS-CoV-2' and gametes, embryos, reproductive function, fertility and ART. Non-English studies and papers published prior to 2020 were excluded, as well as reviews and non-peer reviewed publications. Full papers were assessed for relevance and quality, where feasible.

OUTCOMES

From the 148 papers included, the following observations were made. The SARS-CoV-2-binding proteins, angiotensin-converting enzyme 2 (ACE2) and type II transmembrane serine protease (TMPRSS2), are expressed in the testis, but co-expression remains to be proven. There is some evidence of SARS-CoV-2 RNA in the ejaculate of COVID-19 patients with severe disease, but not in those with mild/moderate disease. SARS-CoV-2 infection can impair spermatogenesis, but this seems to resolve after one spermatogenic cycle. Testosterone levels seem to be lower during and after COVID-19, but long-term data are lacking; disease severity may be associated with testosterone levels. COVID-19 cannot be considered a sexually transmitted disease. There is no co-expression of ACE2 and TMPRSS2 in the myometrium, uterus, ovaries or fallopian tubes. Oocytes seem to have the receptors and protease machinery to be susceptible to SARS-CoV-2 infection; however, viral RNA in oocytes has not been detected so far. Women contemplating pregnancy following COVID-19 may benefit from screening for thyroid dysfunction. There is a possible (transient) impact of COVID-19 on menstrual patterns. Embryos, and particularly late blastocysts, seem to have the machinery to be susceptible to SARS-CoV-2 infection. Most studies have not reported a significant impact of COVID-19 on ovarian reserve, ovarian function or follicular fluid parameters. Previous asymptomatic or mild SARS-CoV-2 infection in females does not seem to negatively affect laboratory and clinical outcomes of ART. There are no data on the minimum required interval, if any, between COVID-19 recovery and ART. There is no evidence of a negative effect of SARS-CoV-2 vaccination on semen parameters or spermatogenesis, ovarian function, ovarian reserve or folliculogenesis. A transient effect on the menstrual cycle has been documented. Despite concerns, cross reactivity between anti-SARS-CoV-2 spike protein antibodies and Syncytin-1, an essential protein in human implantation, is absent. There is no influence of mRNA SARS-CoV-2 vaccine on patients' performance during their immediate subsequent ART cycle. Pregnancy rates post-vaccination are similar to those in unvaccinated patients.

WIDER IMPLICATIONS

This review highlights existing knowledge on the impact of SARS-CoV-2 infection or COVID-19 on fertility and assisted reproduction, but also identifies gaps and offers suggestions for future research. The knowledge presented should help to provide evidence-based advice for practitioners and couples contemplating pregnancy alike, facilitating informed decision-making in an environment of significant emotional turmoil.

Effect of inactivated COVID-19 vaccination on pregnancy outcomes following frozen-thawed embryo transfer: A retrospective cohort study

OBJECTIVE

To investigate the effect of inactivated coronavirus disease 2019 (COVID-19) vaccination on frozen-thawed embryo transfer (FET) outcomes.

METHODS

This retrospective cohort study enrolled 1,210 patients undergoing FET cycles in a single university-affiliated hospital between July 1, 2021, and May 1, 2022. Of them, 387 women with two full doses of inactivated SARS-CoV-2 vaccines (CoronaVac or BBIBP-CorV) after oocyte retrieval were assigned to the vaccinated group, while 823 were unvaccinated as controls. Propensity score matching and multiple regression analysis were applied to control for baseline and cycle characteristics (19 covariates in total).

RESULTS

There were 265 patients in each group after matching. The rates of clinical pregnancy (58.5% vs. 60.8%; P = 0.595) and live birth (44.4% vs. 48.8%; P = 0.693) were similar between vaccinated and unvaccinated patients, with adjusted odds ratios of 0.89 (95% confidence interval [CI] 0.61-1.29) and 1.31 (95% CI 0.37-4.56), respectively. Consistently, no significant differences were found in serum human chorionic gonadotropin levels as well as biochemical pregnancy, biochemical pregnancy loss, and embryo implantation rates. Based on the time interval from vaccination to FET, vaccinated patients were further subdivided into two categories of ≤2 months and >2 months, and the outcomes remained comparable.

CONCLUSION

Our study showed that inactivated COVID-19 vaccination in women did not have measurable detrimental impact on implantation performance and live birth outcome during FET treatment cycles. This finding denies the impairment of endometrial receptivity and trophoblast function by vaccine-induced antibodies at the clinical level.

Past COVID-19: The Impact on IVF Outcomes Based on Follicular Fluid Lipid Profile

Follicular fluid is an important component of follicle growth and development. Negative effects of COVID-19 on follicular function are still open. The aim of this work was to study the features of the lipid profile of follicular fluid and evaluate the results of the in vitro fertilization (IVF) program in women after COVID-19 to identify biomarkers with prognostic potential. The study involved samples of follicular fluid collected from 237 women. Changes in the lipid composition of the follicular fluid of patients who underwent COVID-19 in mild and severe forms before entering the IVF program and women who did not have COVID-19 were studied by mass spectrometry. Several lipids were identified that significantly changed their level. On the basis of these findings, models were developed for predicting the threat of miscarriage in patients who had a severe course of COVID-19 and models for predicting the success of the IVF procedure, depending on the severity of COVID-19. Of practical interest is the possibility of using the developed predictive models in working with patients who have undergone COVID-19 before entering the IVF program. The results of the study suggest that the onset of pregnancy and its outcome after severe COVID-19 may be associated with changes in lipid metabolism in the follicular fluid.