During 1970’s Patrick Steptoe and Robert Edwards, introduced Assisted Reproductive Technique(ART) in Humans. Ever since then in-vitro fertilisation has been evolving and delivering wonders across , the techniques , technologies and culturing criteria for human gametes have been developing , which has definitely proven better results leading to live birth. These changes in embryo culture system include advancement in culture media , approaches towards embryo culturing platforms , use and working of incubators , protocols for ART lab standards and its quality control. Although , every study and research related to different aspect for maintaining and working in lab have been in dispute and several issues , but the main concerns have always been towards better IVF results.
OPTIMISING EMBRYO CULTURE SYSTEM
Over the last 40 years , it is justified to say that the methods of culturing gametes and embryos have changed drastically. However , many of the widely used techniques and approaches have been under dispute for its working and ethical issues now. From the technique of picking up ovum to maturation of egg to culturing embryo to better quality until it is implanted. Continuous researches have led to better vision and correction of under lying issues.
Gametes and embryo culture media
The ideology behind culture media was introduced by Bernard during late1800s which stated that the environment surrounding living tissues and gametes could be formulated to facilitate the suitable fluid specially for gamete culture. A culture medium is a foreign fluid environment designed for the human gametes and embryo. The accuracy of media is complicated because the components must be selected, and their concentrations determined in order to minimise stress for the cultured gametes and embryos. Interestingly, culture media evolved and the clinical media were constructed to support the development of somatic cell culture , followed by first in-vitro oocyte maturation was accomplished by maternal serum converted into biological media. Soon researches stated advancements in the media culture different prospectives followed by different components essential for ideal culture medium were stated. It then became very clear about the components essential for culture medium , these key components are :- Carbohydrates , amino acids , EDTA , ph and buffers , growth factors , regulation of cell volume , macromolecules and macromolecules (vitamins & minerals) , antibiotics. Around 1980s , media commercially available was prepared in every lab as per usage by combination of different components. But now the commercially available media is ready to use with desired component. There has been no study as yet that has compared and evaluated all available media in a controlled criteria , that leads to NO OPTIMAL RECIPE. Presently, the embryo culture media is grouped among single-step media and sequential media , where both the media has potential benefits of their approach. Because commercially used media does not have mentioned concentrations of media components , it is biased to comment on the mechanism of these media. Recently , several single step media are used with time lapse technology . This research criteria has proven to provide better outcome , for valid reason upon less handling and stress to the embryo. Undoubtedly , the compositions of these media is factor restricting the clinician to choose media , making the approach difficult.
Advances in Embryo culture incubator
The primary function of an incubator within IVF laboratory is to provide a stable environment to optimise gamete and embryo development in-vitro conditions. To achieve this goal incubator must regulate several environmental variables including Gas monitoring and recovery, temperature maintenance and to regulate humidity (Swain., 2014). Although the use of conventional incubators have been common for many years and is the routine protocol in embryology laboratories, but this system has limitation due to the need to maximally reducing the frequency of door opening in order to maintain an optimal internal atmosphere, thereby promoting embryo development. On the other hand, a single observation represents an inaccurate method for embryo assessment in terms of detecting abnormal cleavage events or multi nucleation. EmbryoScope time- lapse incubator, which is capable of performing embryo culture in stable and controlled conditions. Time-lapse monitoring may provide more information of embryonic development compared to culture in standard incubator. Essentially, EmbryoScope allows compression of the entire course of embryo evolution into a short video.This technology can potentially progress in chronological analyses and dynamic embryo developments, which can make a crucial contribution to ART. Also EmbryoScope purifies the gas in the chamber by constant recirculation through inactive carbon filter, a HEPA filter, to efficiently delete volatile organic compounds contaminants that can negatively affect embryo quality. Embryoscope incubator displays minimal variation of temperature and gas concentrations when doors are opened as well as a fast recovery to optimal conditions compared with the larger incubators. However beside the various applications of embryo scope time-lapse incubators, concerns have been raised regarding the safety of the time-lapse incubator, considering the exposure to light during the image acquisition. It has been reported that considerable light exposure may be detrimental to embryo development. Furthermore, the presence of a magnetic field, the warmth created by moving parts, and the presence of lubricants may represent an extra risk and might be detrimental to embryo development.
APPROACHES TO IMPROVE EMBRYO CULTURE BY AIR QUALITY CONTROL IN IVF LABORATORY
Air quality control within the in vitro fertilization (IVF) laboratory is one of the major determinants of the assisted reproduction success, as it has significantly shown increase in parameters such as live birth rates. During the 1990s, approaches to indoor air quality emerged in the IVF laboratory: the clean room philosophy that focused on filtration of particles using high efficiency particulate air filters (HEPA) and the chemical air filtration philosophy that focused on removal of volatile organic compounds (VOCs) with solid-phase filtration. Researches on factors that impact air quality identified medical gasses (CO2 ), incubators , and plastic ware as contributors to VOCs in the lab, which led to the development of the incubator chamber air filter. Preliminary results of the Coda were promising, with reports of increased clinical pregnancy rates and decreased miscarriage rates. The second era of air quality in IVF laboratories began at the start of the twenty-first century, as awareness of a relationship between indoor air quality and IVF outcomes resulted in new air quality approaches like Particulate filtration is often associated with cleanrooms because specifications are well established in sectors such as the semiconductor industry. These classifications are based on several factors, including the class of HEPA filter, room air exchanges per hour, and air pressure relative to neighboring rooms. However, studies indicates use of HEPA filtration without providing particle counts, suggesting that particle counts and cleanroom designation were not a primary consideration for the design of the systems. Chemical air filtration, unlike filtration for particulates, is far from standardisation. The amount and form of activated carbon and oxidising media (KMnO4) varies considerably among different types of filters.The challenge of chemical air filtration is effective scrubbing handling a large and variable VOC load in the presence of varying relative humidity. A relatively new method for removing VOCs is ultraviolet photo catalytic oxidation (UVPCO) often combined with carbon filters. While some studies noted an improvement in either laboratory or clinical outcomes or both, nearly every study performed an unmatched, retrospective analysis that did not account for possible differences in patient populations and practice changes that could be responsible for the observed outcomes. Portable air filtration units are available with carbon filtration or with UVPCO. Data on effectiveness of these portable units is minimal, though portable carbon filtration and UVPCO units in an IVF laboratory reduced concentrations of VOCs.In order to determine the extent that a laboratory should filter its air, we need to know what the species and the concentration of VOCs that are harmful for gametes and embryos. This is a challenge because of the variable nature of different VOCs in room air. Since indoor air quality is impacted by outdoor air, which varies regionally, the observation that air pollution affects fertility provides further evidence for the importance of air filtration.
Assisted Reproductive Technology (ART) with In-Vitro Fertilisation(IVF) has no doubt worked wonders for couples who had adoption as the only option. However , continued improvement in reproductive efficacy has been an ongoing endeavour. Over the past decade new technologies and techniques have overall elevated the success rate of ivf , both in terms of embryo culture quality and live birth rate. Looking into advancement like time lapse embryo-scope , single step culture media , air purifiers have overall improved the quality and working conditions. Continuing researches and development into gametes and embryo physiology , quality will help facilitate future improvement of culture media, culture conditions, and optimisation of laboratory procedural techniques.