Navigating assisted reproduction treatment in the time of COVID-19: concerns and considerations

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.

SARS-CoV-2 can infect human embryos

The spread of SARS-CoV-2 has led to a devastating pandemic, with infections resulting in a range of symptoms collectively known as COVID-19. The full repertoire of human tissues and organs susceptible to infection is an area of active investigation, and some studies have implicated the reproductive system. The effects of COVID-19 on human reproduction remain poorly understood, and particularly the impact on early embryogenesis and establishment of a pregnancy are not known. In this work, we explore the susceptibility of early human embryos to SARS-CoV-2 infection. By using RNA-seq and immunofluorescence, we note that ACE2 and TMPRSS2, two canonical cell entry factors for SARS-CoV-2, are co-expressed in cells of the trophectoderm in blastocyst-stage preimplantation embryos. For the purpose of viral entry studies, we used fluorescent reporter virions pseudotyped with Spike (S) glycoprotein from SARS-CoV-2, and we observe robust infection of trophectoderm cells. This permissiveness could be attenuated with blocking antibodies targeting S or ACE2. When exposing human blastocysts to the live, fully infectious SARS-CoV-2, we detected cases of infection that compromised embryo health. Therefore, we identify a new human target tissue for SARS-CoV-2 with potential medical implications for reproductive health during the COVID-19 pandemic and its aftermath.

Impact of COVID-19 on fertility and assisted reproductive technology (ART): a systematic review

The appearance of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a major obstacle for the performing of current medical activities throughout the world. COVID-19 has affected humanity in many ways, thus causing a great medical, social, economic, and political instability. The aim of this study was to make an analysis of the scientific data obtained by so far to highlight the impact that COVID-19 has had on fertility and assisted reproductive technology (ART). Infection with SARS-CoV-2 alters the normal immune response by local and systemic damage to tissues and organs. After the virus enters the body, the first lesions are produced in the respiratory tract. Extrapulmonary lesions specific to COVID-19 include acute renal lesions/acute kidney damage, hepatocellular lesions, neurological diseases, myocardial dysfunction and arrhythmia, gastrointestinal diseases but also genital impairment. The possible impairment of the male reproductive system is because angiotensin-converting enzyme 2 (ACE2) receptors are in an increased number in the testes, seminiferous duct cells, spermatogonia, Leydig cells and Sertoli cells. Many published studies to date have pointed out that COVID-19 could also affect female fertility and disrupt the functions of the female reproductive system. The theory that this virus can also be transmitted sexually and can cause infertility or testicular damage is supported by the fact that the virus can be isolated in the semen of COVID-19 patients but only during the disease. Choosing the best method of treating infertility during the COVID-19 pandemic is multifactorial, but the risk of infection and compliance with specific ART hygiene protocols must always be considered. Currently, there is no scientific basis regarding the fact that the COVID-19 vaccination would influence fertility.

Obstetric challenges during COVID-19 pandemic: A narrative review

The severe acute respiratory coronavirus 2 (COVID-19) pandemic impacts the health of women at reproductive age in different ways, starting from pregnancy planning to post-delivery. This narrative review summarises the challenges to obstetric practice posed by the severe acute respiratory coronavirus 2 (COVID-19) pandemic. In this paper, we highlight the impacts of COVID-19 to obstetric practice globally and the efforts taken to address these challenges. Further study is critical to investigate the effects of COVID-19 on pregnancy, the outcome of COVID-19 positive pregnant women, and the safety of vaccination during pregnancy and breastfeeding.

Controlled Ovarian Hyperstimulation Protocol in Infertile Patients During the COVID-19 Pandemic

Objectives: To explore the appropriate controlled ovarian hyperstimulation (COH) protocols in infertility patients who received the in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatments during the COVID-19 pandemic.

Materials and Methods: This retrospective cohort study evaluated the efficiency of the early follicular-phase long-acting GnRH-agonist long (EFLL) protocol (a new protocol developed by Chinese clinicians), prolonged pituitary down-regulation of EFLL protocol (Pro-EFLL), and the GnRH-ant protocol for couples meeting the study criteria between February 2020 and June 2020 who were treated by the First Affiliated Hospital of Zhengzhou University during the COVID-19 pandemic, and compared the pregnancy rates and miscarriage rates per fresh transfer cycle, number of retrieved oocytes, endometrial thickness on the day of hCG injection and the number of fertilized oocytes, mature oocytes, fertilized oocytes, and transferable embryos among the three protocols.

Results: We found that the prolonged pituitary down-regulation during the COVID-19 pandemic by utilizing a full-dose of GnRH-a administrated in infertility patients were no differences in clinical outcomes than other protocols, The prolonged pituitary down-regulation protocol and EFLL protocol were associated with a higher Endometrial thickness on the day of hCG injection (12.67 ± 2.21 vs. 12.09 ± 2.35 vs. 10.79 ± 2.38, P < 0.001), retrieved oocytes (14.49 ± 6.30 vs. 15.02 ± 7.93 vs. 10.06 ± 7.63, P < 0.001), mature oocytes (11.60 ± 5.71 vs. 11.96 ± 6.00 vs. 7.63 ± 6.50, P < 0.001), fertilized oocytes (9.14 ± 5.43 vs. 8.44 ± 5.34 vs. 5.42 ± 5.20, P < 0.001), and transferable embryos (4.87 ± 2.96 vs. 6.47 ± 5.12 vs. 3.00 ± 3.28 vs. P < 0.001) in the GnRH-antagonist protocol.

Conclusion: We recommend that patients start Gn injections 33–42 days after a pituitary downregulated full dose (3.75 mg) of gonadotropin-releasing hormone agonist during the COVID-19 pandemic, even a delay of 2–4 weeks does not affect the implantation rate. The study can provide a more detailed estimate and clinical management strategies for infertile couples during the COVID-19 pandemic.

The Current Evidence Regarding COVID-19 and Pregnancy: Where Are We Now and Where Should We Head to Next?

Despite the volume of publications dedicated to unraveling the biological characteristics and clinical manifestations of SARS-CoV-2, available data on pregnant patients are limited. In the current review of literature, we present an overview on the developmental course, complications, and adverse effects of COVID-19 on pregnancy. A comprehensive review of the literature was performed in PubMed/Medline, Embase, and Cochrane Central databases up to June 2021. This article collectively presents what has been so far reported on the identified critical aspects, namely complications during pregnancy, delivery challenges, neonatal health care, potential routes of viral transmission, including vertical transmission or breastfeeding, along with the risks involved in the vaccination strategy during pregnancy. Despite the fact that we are still largely navigating uncharted territory, the observed publication explosion in the field is unprecedented. The overwhelming need for data is undoubtable, and this serves as the driver for the plethora of publications witnessed. Nonetheless, the quality of data sourced is variable. In the midst of the frenzy for reporting on SARS-CoV-2 data, monitoring this informational overload is where we should head to next, considering that poor quality research may in fact hamper our attempts to prevail against this unparalleled pandemic outbreak.

Multiple regression analysis of perinatal conditions, physical development, and complications in assisted reproduction singletons

BACKGROUND

There is no clear clinical conclusion on whether assisted reproductive technology (ART) increases maternal and child risk and affects infant birth and development. This study aimed to perform a multiple regression analysis of the perinatal maternal and infant conditions in an assisted reproductive singleton pregnancy and the physical development and complications of such infants at 6 months old.

METHODS

This study enrolled 145 singleton pregnant women who were admitted to Luohe Central Hospital between December 2017 and December 2019 to undergo in vitro fertilization and embryo transfer as a research group, and 160 singleton pregnant women who were naturally conceived at the same time and delivered at our hospital were selected as the control group. The relevant data of the patients were collected, and the perinatal conditions, neonatal complications, physical development and NBN score of infants aged 6 months were compared between the two groups. Multivariate logistic regression was used to analyze risk factors for perinatal complications in assisted reproduction singleton pregnancy.

RESULTS

The incidence of complications in the perinatal period in the study group was significantly higher than that in the control group (P<0.05). However, there was no significant difference in the incidence of complications such as very low birth weight, respiratory distress, neonatal hemolysis, hyperbilirubinemia, hypoglycemia, infectious pneumonia and neonatal asphyxia between the two groups (P>0.05). Likewise, at 6 months of age, the infants in the research group showed no significant difference to the control group in physical development indicators, including weight, head circumference, body mass index, height and NBN score (P>0.05). The analysis of the unconditional multivariate logistic regression model revealed hypertension during pregnancy, placental previa, premature membrane rupture, gestational age <32 weeks, and very low birth weight as risk factors that affect perinatal complications in patients with assisted reproductive singleton pregnancy (P<0.05).

CONCLUSIONS

The incidence of complications in perinatal patients with assisted reproductive singleton pregnancy is higher than that of natural singleton pregnancy, but there is no significant difference in physical development, NBN score and complications of 6 months old infants.

Expression map of entry receptors and infectivity factors for pan-coronaviruses in preimplantation and implantation stage human embryos

PURPOSE

To predict if developing human embryos are permissive to multiple coronaviruses.

METHOD

We analyzed publicly available single-cell RNA-seq datasets of human embryos for the known canonical and non-canonical receptors and spike protein cleavage enzymes for multiple coronaviruses like SARS-CoV, SARS-CoV-2, MERS-CoV, hCoV-229E, and hCoV-NL63. We also analyzed the expression of host genes involved in viral replication, host proteins involved in viral endosomal sorting complexes required for transport (ESCRT), genes of host proteins that physically interact with proteins of SARS-CoV-2, and the host genes essential for coronavirus infectivity.

RESULTS

Of the known receptors of SARS viruses, ACE2, BSG, GOLGA7, and ZDHHC5 were expressed in different proportions in the zygote, 4-cell, 8-cell, morula, and blastocysts including the trophectoderm. The MERS-CoV receptor, DPP4, and hCoV-229E receptor, ANPEP, were expressed mainly from the compact morula to the blastocyst stages. Transcripts of the MERS-CoV alternate receptor LGALS1 were detected in most cells at all stages of development. TMPRSS2 transcripts were detected in the epiblast, primitive endoderm, and trophectoderm, while transcripts of the endosomal proteases CTSL, CTSB, and FURIN were expressed in most cells at all stages of development. ACE2 and TMPRSS2 were co-expressed in a proportion of epiblast and trophectoderm cells. The embryonic cells expressed genes involved in ESCRT, viral replication, SARS-CoV-2 interactions, and coronavirus infectivity. The ACE2 and TMPRSS2 co-expressing cells were enriched in genes associated with lipid metabolism, lysosome, peroxisome, and oxidative phosphorylation pathways.

CONCLUSION

Preimplantation and implantation stage human embryos could be permissive to multiple hCoVs.

How to provide fertility treatment during COVID-19 pandemic

PURPOSE OF REVIEW

The emergence of the novel coronavirus infection that arose in Wuhan, China in December 2019 has resulted in an epidemic that has quickly expanded to become one of the most significant public health threats in recent times. The objective of this review is to summarize how this pandemic has affected the activity of a Reproductive Medicine Center, which established a series of measures in parallel with governments decisions and scientific societies.

RECENT FINDINGS

The control measures adopted for restarting the healthcare activity should be equitable and inclusive. Moreover, this pandemic has implied changes in treatments and strategies to be alert regarding the daily changing information. Finally, for ensuring a safe practice both for patients and staff, it is important to detect asymptomatic patients, so Reproductive Medicine centers must take special care with screening and testing procedures.

SUMMARY

The pandemic has pushed up toward a new reality in terms of Assisted Reproductive treatments, where social distance and responsibility are protagonists. We face a new challenge of balancing between responding to the committed efforts of infertile couples to achieve pregnancy and safeguarding the health of the future parents and their children during this time of pandemic.

Absence of SARS-CoV-2 (COVID-19 virus) within the IVF laboratory using strict patient screening and safety criteria

Research question

Is there a risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral exposure and potential cross-contamination from follicular fluid, culture media and vitrification solution within the IVF laboratory using strict patient screening and safety measures?

Design

This was a prospective clinical study. All women undergoing transvaginal oocyte retrieval were required to have a negative SARS-CoV-2 RNA test 3–5 days prior to the procedure. Male partners were not tested. All cases used intracytoplasmic sperm injection (ICSI). The first tube of follicular fluid aspirated during oocyte retrieval, drops of media following removal of the embryos on day 5, and vitrification solution after blastocyst cryopreservation were analysed for SARS-CoV-2 RNA.

Results

In total, medium from 61 patients, vitrification solution from 200 patients and follicular fluid from 300 patients was analysed. All samples were negative for SARS-CoV-2 viral RNA.

Conclusions

With stringent safety protocols in place, including testing of women and symptom-based screening of men, the presence of SARS-CoV-2 RNA was not detected in follicular fluid, medium or vitrification solution. This work demonstrates the possibility of implementing a rapid laboratory screening assay for SARS-CoV-2 and has implications for safe laboratory operations, including cryostorage recommendations.