Live births achieved via IVF are increased by improvements in air quality and laboratory environment

Embryo development, pregnancy and live birth outcomes following IVF treatment were not compromised during the COVID-19 pandemic

PURPOSE

To evaluate whether outcomes of in vitro fertilization (IVF) are affected during the coronavirus disease-19 (COVID-19) pandemic.

METHODS

This was a single-center, retrospective study. Embryo development, pregnancy, and live birth outcomes were compared between COVID-19 and pre-COVID-19 groups. Blood samples from patients during the COVID-19 pandemic were tested for COVID-19.

RESULTS

After 1:1 random matching, 403 cycles for each group were included in the study. The rates of fertilization, normal fertilization, and blastocyst formation were higher in the COVID-19 group than in the pre-COVID-19 group. No difference was observed in the rates of day 3 good-quality embryos and good-quality blastocysts between the groups. A multivariate analysis showed that the live birth rate in the COVID-19 group was higher than that in the pre-COVID-19 group (51.4% vs. 41.4%, P = 0.010). In fresh cleavage-stage embryo and blastocyst transfer cycles, there were no differences between the groups in terms of pregnancy, obstetric, and perinatal outcomes. In the freeze-all cycles, the live birth rate was higher during the COVID-19 pandemic (58.0% vs. 34.5%, P = 0.006) than during the pre-COVID-19 period following frozen cleavage stage embryo transfer. The rate of gestational diabetes during the COVID-19 pandemic was higher than that during the pre-COVID-19 period (20.3% vs. 2.4%, P = 0.008) following frozen blastocyst transfer. All the serological results of the patients during the COVID-19 pandemic were negative.

CONCLUSION

Our results indicate that embryo development, pregnancy, and live birth outcomes in uninfected patients were not compromised during the COVID-19 pandemic at our center.

Modelling the equilibrium partitioning of low concentrations of airborne volatile organic compounds in human IVF laboratories

RESEARCH QUESTION

Can volatile organic compounds (VOC) be modelled in an IVF clinical setting?

DESIGN

The study performed equilibrium modelling of low concentrations of airborne VOC partitioning from the air phase into the oil cover layer into the water-based culture media and into/onto the embryo (air-oil-water-embryo). The air-phase VOC were modelled based on reported VOC concentrations found in modern assisted reproductive technology (ART) suites, older IVF clinics, and hospitals, as well as at 10 parts per billion (ppb) and 100 ppb for all compounds. The modelling was performed with 23 documented healthcare-specific VOC.

RESULTS

Based on the partitioning model, seven compounds (acrolein, formaldehyde, phenol, toluene, acetaldehyde, ethanol and isopropanol) should be of great concern to the embryologist and clinician. Acrolein, formaldehyde, phenol, toluene and acetaldehyde are the VOC with the most potent cytotoxic factor and the highest toxic VOC concentration in media. In addition, ethanol and isopropanol are routinely found in the greatest air-phase concentrations and modelled to have the highest water-based culture concentrations.

CONCLUSIONS

The results of the equilibrium partitioning modelling of VOC provides a fundamental understanding of how airborne VOC partition from the air phase and negatively influence human IVF outcomes. The results presented here are based on the theoretical model and the values presented have not yet been measured in a laboratory or clinical setting. High air-phase concentrations and toxic concentrations of VOC in culture media are likely indicators of poor clinical outcomes. Based on this model, improved air quality in IVF laboratories reduces the chemical burden imparted on embryos, which supports findings of improved IVF outcomes with reduced air-phase VOC concentrations.

Effects of air pollution on clinical pregnancy rates after in vitro fertilisation (IVF): a retrospective cohort study

OBJECTIVE

To evaluate the effect of air pollution, from oocyte retrieval to embryo transfer, on the results of in vitro fertilisation (IVF) in terms of clinical pregnancy rates, at two fertility centres, from 2013 to 2019.

DESIGN

Exploratory retrospective cohort study.

SETTING

This retrospective cohort study was performed in the Reproductive Biology Department of Bordeaux University Hospital localised in Bordeaux, France and the Jean Villar Fertility Center localised in Bruges, France.

PARTICIPANTS

This study included 10 763 IVF attempts occurring between January 2013 and December 2019, 2194 of which resulted in a clinical pregnancy.

PRIMARY AND SECONDARY OUTCOME MEASURES

The outcome of the IVF attempt was recorded as the presence or absence of a clinical pregnancy; exposure to air pollution was assessed by calculating the cumulative exposure of suspended particulate matter, fine particulate matter, black carbon, nitrogen dioxide and ozone (O₃₎, over the period from oocyte retrieval to embryo transfer, together with secondary exposure due to the presence of the biomass boiler room, which was installed in 2016, close to the Bordeaux University Hospital laboratory. The association between air pollution and IVF outcome was evaluated by a random-effects logistic regression analysis.

RESULTS

We found negative associations between cumulative O₃ exposure and clinical pregnancy rate (OR=0.92, 95% CI = (0.86 to 0.98)), and between biomass boiler room exposure and clinical pregnancy rate (OR=0.75, 95% CI = (0.61 to 0.91)), after adjustment for potential confounders.

CONCLUSION

Air pollution could have a negative effect on assisted reproductive technology results and therefore precautions should be taken to minimise the impact of outdoor air on embryo culture.

Associations between ambient air pollution and IVF outcomes in a heavily polluted city in China

RESEARCH QUESTION

Is air pollution related to IVF outcomes in a heavily polluted city in China?

DESIGN

A retrospective cohort study of 8628 fresh, autologous IVF cycles was conducted for the first time at the Reproductive Medicine Center of The Third Affiliated Hospital of Zhengzhou University between May 2014 and December 2018 (oocyte retrieval date). The exposure was divided into four periods (gonadotrophin injection to oocyte retrieval [P1], oocyte retrieval to embryo transfer [P2], 1 day after embryo transfer to embryo transfer +14 days [P3] and gonadotrophin injection to embryo transfer +14 days [P4]) and four levels (Q1-Q4 according to their 25th, 50th and 75th percentiles).

RESULTS

An interquartile range increase (Q2 versus Q1) in particulate matter ≤10 µm (PM10) during P3 and P4 and sulphur dioxide (SO₂) during P3 significantly decreased the clinical pregnancy rate (adjusted odds ratio [aOR] 0.81, 95% confidence interval [CI] 0.71-0.92 for PM10 of P3; aOR 0.87, 95% CI 0.76-1.00 for PM10 of P4; aOR 0.82, 95% CI 0.73-0.93 for SO₂ of P3). In addition, PM10 was associated with an increased biochemical pregnancy rate (Q3 versus Q1: aOR 1.55, 95% CI 1.09-2.19 for PM10 of P1) and decreased live birth rate (Q2 versus Q1: aOR 0.88, 95% CI 0.77-0.99 for PM10 of P3). The multivariate regression results were consistent with that of multiple treatments propensity score method (PSM) for SO₂ pollutants in P3 and PM10 pollutants in P4.

CONCLUSION

From the early follicular stage to the pregnancy test period, high concentrations of PM10 and SO₂ may have a negative impact on IVF treatment outcomes in the study area.

Off-gassing plasticware to decrease the toxicity effect in embryo culture

Objective:

Methods:

Results:

Conclusions:

Air quality in the clinical embryology laboratory: a mini-review

The scope of the clinical embryology laboratory has expanded over recent years. It now includes conventional in vitro fertilization (IVF) techniques and complex and time-demanding procedures like blastocyst culture, processing of surgically retrieved sperm, and trophectoderm biopsy for preimplantation genetic testing. These procedures require a stable culture environment in which ambient air quality might play a critical role. The existing data indicate that both particulate matter and chemical pollution adversely affect IVF results, with low levels for better outcomes. As a result, IVF clinics have invested in air cleaning technologies with variable efficiency to remove particulates and volatile organic compounds. However, specific regulatory frameworks mandating air quality control are limited, as are evidence-based guidelines for the best air quality control practices in the embryology laboratory. In this review, we describe the principles and existing solutions for improving air quality and summarize the clinical evidence concerning air quality control in the embryology laboratory. In addition, we discuss the gaps in knowledge that could guide future research to improve clinical outcomes.

Ambient air pollution and in vitro fertilization treatment outcomes

STUDY QUESTION

Is air pollution associated with IVF treatment outcomes in the USA?

SUMMARY ANSWER

We did not find clear evidence of a meaningful association between reproductive outcomes and average daily concentrations of particulate matter with an aerodynamic diameter ≤2.5 μm (PM2.5) and ozone (O3).

WHAT IS KNOWN ALREADY

Maternal exposure to air pollution such as PM2.5, nitrogen oxides, carbon monoxide or O3 may increase risks for adverse perinatal outcomes. Findings from the few studies using data from IVF populations to investigate associations between specific pollutants and treatment outcomes are inconclusive.

STUDY DESIGN, SIZE AND DURATION

Retrospective cohort study of 253 528 non-cancelled fresh, autologous IVF cycles including 230 243 fresh, autologous IVF cycles with a transfer of ≥1 embryo was performed between 2010 and 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We linked 2010-2012 National ART Surveillance System data for fresh, autologous IVF cycles with the ambient air pollution data generated using a Bayesian fusion model available through the Centers for Disease Control and Prevention's Environmental Public Health Tracking Network. We calculated county-level average daily PM2.5 and O3 concentrations for three time periods: cycle start to oocyte retrieval (T1), oocyte retrieval to embryo transfer (T2) and embryo transfer +14 days (T3). Multivariable predicted marginal proportions from logistic and log-linear regression models were used to estimate adjusted risk ratios (aRR) and 95% CI for the association between reproductive outcomes (implantation rate, pregnancy and live birth) and interquartile increases in PM2.5 and O3. The multipollutant models were also adjusted for patients and treatment characteristics and accounted for clustering by clinic and county of residence.

MAIN RESULTS AND THE ROLE OF CHANCE

For all exposure periods, O3 was weakly positively associated with implantation (aRR 1.01, 95% CI 1.001-1.02 for T1; aRR 1.01, 95% CI 1.001-1.02 for T2 and aRR 1.01, 95% CI 1.001-1.02 for T3) and live birth (aRR 1.01, 95% CI 1.002-1.02 for T1; aRR 1.01, 95% CI 1.004-1.02 for T2 and aRR 1.02, 95% CI 1.004-1.03 for T3). PM2.5 was not associated with any of the reproductive outcomes assessed.

LIMITATIONS, REASONS FOR CAUTION

The main limitation of this study is the use of aggregated air pollution data as proxies for individual exposure. The weak positive associations found in this study might be related to confounding by factors that we were unable to assess and may not reflect clinically meaningful differences.

WIDER IMPLICATIONS OF THE FINDINGS

More research is needed to assess the impact of air pollution on reproductive function.

STUDY FUNDING/COMPETING INTEREST(S)

None.

Recent trends in embryo disposition choices made by patients following in vitro fertilization

PURPOSE

To assess longitudinal trends in in vitro fertilization (IVF) patients' choices for disposing of cryopreserved embryos.

METHODS

This is a retrospective cohort study of embryo disposition forms submitted between January 2000 and February 2020 at a university-based fertility clinic. Primary outcome was disposition decision. Binary and multivariable logistic regression were performed to determine odds ratios (OR) for decisions according to female age, education, race, religion, state of residence, area deprivation index based on zip code, and IVF pregnancy history. We also assessed disposition year, storage duration, and number of stored embryos.

RESULTS

Forms were reviewed from 615 patients; 50.6% chose to discard embryos, 45.4% donated to research, and 4.1% chose reproductive donation. In the regression model, two factors were significantly associated with donation to research: female listing "no preference" or declining to list religious preference (OR 2.56, 95%CI 1.44-4.54) and live birth of multiples after IVF (OR 1.58, 95%CI 1.05-2.36). Before 2012, females younger than age 30 at storage were equally likely to choose to donate embryos to research as discard them. However, between 2013 and 2020, females younger than 30 were significantly more likely to discard than donate embryos for research (OR 2.87, 95%CI 1.13-7.28).

CONCLUSION

Since 2013, the majority of patients younger than 30 at storage have chosen to discard cryopreserved embryos. Before then, patients were more likely to donate embryos for research. To ensure sufficient embryos are available for research, young patients, who are most likely to have cryopreserved embryos, should be counseled about options for donation.

[Impact of air quality on practices and results in the IVF laboratory]

The concept of Air Quality often refers to particulate and microbiological contamination of ambiant air. European Directive 2006/86/CE encompass the IVF process and specify a class A air quality for manipulation of tissue and cells, in a class D environment (A over D rule). Recognizing the paramount importance of ensuring the highest microbiological and particulate safety in the IVF laboratory, it is equally important to take into account practicability issues and the financial burden of these recommendations, as well as the utter need to protect gametes and embryo viability during their IVF journey. The usefulness of such stringent recommendations may also be questionned given the absence of published cases of airborne contaminations and related patients infections after embryo transfer. The European directive stems from pharmaceutical standards and were not specifically designed for human IVF. Gametes and embryos are indeed extremely sensitive to physical and chemical stress and require strict temperature, osmolarity and pH control, as well as an absence of chemical contamination during manipulation and culture. These conditions are hardly obtained when using laminar flow hoods. Following concerns raised by many experts in the field, exceptions to the A over D rule were added in the 2006/86/CE Directives. This narrative review discusses all these aspects in a critical way and compare scientific and legal requirements applying to IVF practices in different regions of the world.

Considerations Regarding Embryo Culture Conditions: From Media to Epigenetics

There are numerous reports on embryo culture media and conditions in the laboratory, as the subject is multifaceted and complex, reflecting the variation in practice. In this scoping review, we attempt to approach the topic of culture media and conditions from the practitioners' perspective aiming to highlight, in a comprehensive fashion, important aspects regarding the options available, introduce points of debate and controversy, while maintaining the viewpoint of the practicing embryologist's concerns.

Cairo consensus on the IVF laboratory environment and air quality: report of an expert meeting

This proceedings report presents the outcomes from an international Expert Meeting to establish a consensus on the recommended technical and operational requirements for air quality within modern assisted reproduction technology (ART) laboratories. Topics considered included design and construction of the facility, as well as its heating, ventilation and air conditioning system; control of particulates, micro-organisms (bacteria, fungi and viruses) and volatile organic compounds (VOCs) within critical areas; safe cleaning practices; operational practices to optimize air quality while minimizing physicochemical risks to gametes and embryos (temperature control versus air flow); and appropriate infection-control practices that minimize exposure to VOC. More than 50 consensus points were established under the general headings of assessing site suitability, basic design criteria for new construction, and laboratory commissioning and ongoing VOC management. These consensus points should be considered as aspirational benchmarks for existing ART laboratories, and as guidelines for the construction of new ART laboratories.

Air quality control in the ART laboratory is a major determinant of IVF success

A recently published article described how a fertility center in the United States implemented air quality control to newly designed in vitro fertilization (IVF) laboratory.1 A highly-efficient air filtration was achieved by installing a centered system supplying filtered air to the IVF laboratory and related critical areas, combining air particulate and volatile organic compound (VOC) filtration. As a consequence, live birth rates were increased by improvements in air quality. This article highlights the key aspects of air contamination in the IVF context. The topic is important not only to IVF specialists but also to Andrologists due to the great number of male infertility patients referred to assisted reproductive technology (ART) treatments. The evidence is growing that laboratory air quality is paramount importance for improved IVF outcome.

Impact of the IVF laboratory environment on human preimplantation embryo phenotype

The phenotype of the human embryo conceived through in vitro fertilization (IVF), that is its morphology, developmental kinetics, physiology and metabolism, can be affected by numerous components of the laboratory and embryo culture system (which comprise the laboratory environment). The culture media formulation is important in determining embryo phenotype, but this exists within a culture system that includes oxygen, temperature, pH and whether an embryo is cultured individually or in a group, all of which can influence embryo development. Significantly, exposure of an embryo to one suboptimal component of the culture system of laboratory typically predisposes the embryo to become more vulnerable to a second stressor, as has been well documented for atmospheric oxygen and individual culture, as well as for oxygen and ammonium. Furthermore, the inherent viability of the human embryo is derived from the quality of the gametes from which it is created. Patient age, aetiology, genetics, lifestyle (as well as ovarian stimulation in women) are all known to affect the developmental potential of gametes and hence the embryo. Thus, as well as considering the impact of the IVF laboratory environment, one needs to be aware of the status of the infertile couple, as this impacts how their gametes and embryos will respond to an in vitro environment. Although far from straight forward, analysing the interactions that exist between the human embryo and its environment will facilitate the creation of more effective and safer treatments for the infertile couple.

Strategies to improve fertilisation rates with assisted conception: a systematic review

Successful fertilisation is one of the key steps determining success of assisted conception. Various factors including sperm or oocyte pathology and environmental factors have a significant impact on fertilisation rates. This systematic review is aimed to evaluate the existing evidence about factors affecting fertilisation and strategies to improve fertilisation rates. A literature search was performed using Ovid MEDLINE ® (Jan 1950-April 2016), EMBASE (Jan 1950-April 2016), Ovid OLDMEDLINE ®, Pre-MEDLINE (Jan 1950-April 2016) and the Cochrane Library. Relevant key words were used to combine sets of results and a total 243 papers were screened. Only qualitative analysis was performed, as there was major heterogeneity in study design and methodology for quantitative synthesis. Factors affecting fertilisation were divided into sperm- and oocyte-related factors. The methods to improve fertilisation rates were grouped together based on the approach used to improve fertilisation rates. Optimising laboratory condition and procedural effects in techniques is associated with improved fertilisation rates. Various techniques are described to improve fertilisation rates including assisted oocyte activation, physiological intracytoplasmic sperm injection (PICSI) and intracytoplasmic morphologically selected sperm injection (IMSI). This review highlights the promising strategies under research to enhance fertilisation rates. Adequately powered multicentre randomised trials are required to evaluate these techniques before considering clinical application.

Volatile organic compounds and good laboratory practices in the in vitro fertilization laboratory: the important parameters for successful outcome in extended culture

PURPOSE

This study aims to describe the role of implementing good laboratory practices to improve in vitro fertilization (IVF) outcomes which are of great interest for practitioners dealing with infertility.

METHODS

Certain modifications were introduced in May 2015 in our IVF laboratory like high-efficiency particulate air CODA system, steel furniture instead of wooden, use of new disinfectants like oosafe, and restriction of personnel entry along with avoidance of cosmetics like perfume to improve pregnancy rates. Volatile organic compound (VOC) meter reading was monitored at two time points and five different places in the laboratory to compare the embryonic development parameters before (group A: July 2014-April 2015) and after (group B: July 2015-April 2016) remodeling.

RESULTS

The IVF outcomes from 1036 cycles were associated in this study. Reduction in VOC meter readings, enhanced air quality, improvement in blastocyst formation rate, implantation, and clinical pregnancy rate were observed in the laboratory after implementation of new facilities. Results illustrated that the attention must be focused on potential hazards which expose laboratories to elevated VOC levels. Blastocyst formation rate increased around 18%. Implantation rate, clinical pregnancy rate, and live birth rate increased by around 11, 10, and 8%, respectively.

CONCLUSION

In conclusion, with proper engineering and material selection, we have been able to reduce chemical contamination and adverse effects on culture with optimized IVF results.

SUPPORT

None.

Embryo transfer simulation improves pregnancy rates and decreases time to proficiency in Reproductive Endocrinology and Infertility fellow embryo transfers

OBJECTIVE

To design and evaluate an ET simulator to train Reproductive Endocrinology and Infertility (REI) fellows' techniques of ET.

DESIGN

Simulation model development and retrospective cohort analysis.

SETTING

Not applicable.

PATIENT(S)

Patients undergoing IVF.

INTERVENTION(S)

Simulation model evaluation and implementation of ET simulation training.

MAIN OUTCOME MEASURE(S)

Pregnancy rates.

RESULT(S)

The REI fellow and faculty evaluation responses (n = 19/21 [90%]) of the model demonstrated realistic characteristics, with evaluators concluding the model was suitable for training in almost all evaluated areas. A total of 12 REI fellows who performed ET were analyzed: 6 before ET trainer and 6 after ET trainer. Pregnancy rates were 31% in the initial 10 ETs per fellow before simulator vs. 46% after simulator. One of six pre-ET trainer fellows (17%) had pregnancy rates ≥40% in their first 10 ETs; whereas four of six post-ET trainer fellows had pregnancy rates ≥40% in their first 10 ETs. The average number of ETs to obtain >40% pregnancy efficiency was 27 ETs before trainer vs. 15 ETs after trainer. Pregnancy rates were similar in the two groups after 20 ETs, and collective terminal pregnancy rates were >50% after 40 ETs.

CONCLUSION(S)

Embryo transfer simulation improved REI fellow pregnancy rates in their first 10 transfers and led to a more rapid ET proficiency. These data suggest potential value in adopting ET simulation, even in programs with a robust history of live ET in fellowship training.

Implementation of cleanroom technology in reproductive laboratories: the question is not why but how

Two articles recently published in Reproductive BioMedicine Online described how fertility centres in the USA and Brazil implemented air quality control to newly designed facilities. In both case scenarios, a highly efficient air filtration was achieved by installing a centred system supplying filtered air to the IVF laboratory and other critical areas, combining air particulate and volatile organic compound (VOC) filtration. Evaluating retrospective data of over 3000 cycles from both centres, live birth rates were increased by improvements in air quality and laboratory environment. This commentary discusses some of the key aspects of air contamination in the IVF settings, and highlights the fact that a risk management analysis taking into consideration all variables that play a role in air contamination is paramount for the reduction of the risk of poor IVF outcomes due to improper air quality conditions.