Control of air pollution in assisted reproductive technology laboratory and adjacent areas improves embryo formation, cleavage and pregnancy rates and decreases abortion rate: Comparison between a class 100 (IS0 5) and a class 1,000 (IS06) cleanroom

Control of air pollution in assisted reproductive technology laboratory and adjacent area improves embryo formation,cleavage and pregnancy rates and decreases abortion rate: comparison between a Class 100 (ISO 5) and Class 1.000 (ISO 6) cleanroom for micromanipulation and embryo culture.

S. C. Esteves, A. P. Gomes, S. Verza Jr; ANDROFERT – Centro de Referência em Infertilidade Masculina, Campinas, Brazil

Objective: Filtration units have been show to reduce airborne concentrations of toxics volatile organic compounds (VOC), chemical contaminants and particles in IVF laboratories. The aim of this study was to evaluate the impact of high standard measures for air quality control inside the ART laboratory and adjacent areas on fertilization, cleavage, embryo formation, pregnancy and abortion rates. Design: Retrospective cohort study os consecutive IVF-ICSI cycles. All cycles from April 2000 to April 2002 were performed in a Class 1.000 laboratory, while the subsequent ones were performed in a Class 100 laboratory with adjacent cleanroom facilities. Materials and Methods: This studyincluded 468 ICSI cycles from April 2000 to December 2003. Cycles were divided into those performed in a Class 1.000 (ISO 6; n=220) and those in a Class 100 (ISO 5; n=248) cleanroom ART laboratory. Class 1.000 laboratory was equipped witha positive pressure high efficiency particles air filtration (HEPA) system (Veco, Brazil) and a free-standing unit to fliter and remove VOC (CODA Tower, GenX, USA). Class 100 laboratory was built with proper engineering and material selection, and with a dedicated air handling system equiped with HEPA and carbon-impergnated filters (Veco, Brazil) located in a separate room to filter and remove particles and VOC from the ART laboratory and adjacent areas (dressing, operating, embryo and transfer rooms). A positive pressure differential was maintained from Class 100 ART laboratory to the operating (Class 1.000) and embryo transfer rooms (Class 10.000), which were also built as cleanrooms. In-line HEPA and carbon-activated filters were placed from the gas cylinders to incubators, while intra-incubators filtration unita were available for Class 100 ART laboratory. Ovulation induction, techniques, embryo culture and transfer protocols were identical in both groups. Main outcome measures were normal fertilization and cleavage rates, percentage of good quality embryos available for trasfer on day 3, clinical pregnancy and abortion rates. Data were analyzed by Mann Whitney U test or Chi-Square, with P< 0,05 considered significant. Results: Female age, number of oocytes retrieved per cycles, number of embryos transferred were not statistically different between groups. Main results are show in the table. Values are expressed as mean ± SD.

Conclusion: Control of air pollution in ART laboratory, operrating and transfer rooms through the construction ofcleanrooms equipped with carbon-impergnated filters for air and incubators results in better good quality embryo formation, cleavage and pregnancy rates, and in lower spontaneous abortion rates. Our 7observations are consistent with an association between the presence of air contaminants in the ART laboratory and impairment of embrynic development. It would seem also prudent to control air pollution im adjacent areas where other critical steps for ART success take place, such as oocyte collection and embryo transfer rooms. Support: None.