IVF cycle safety when a positive passive air sampling occurs under laminar flow hood in absence of a detectable contamination in the embryo culture.

Microbiological contamination in the embryo culture media might affect embryo early development and clinical outcomes during IVF procedures. Infections in the genital tract represent the most common causes of culture contamination, but also environmental air quality might have a detrimental effect on reproductive outcomes of infertile couples undergoing IVF procedures. Monitoring microbiological contamination in an embryology laboratory is mandatory and daily tests are performed under laminar vertical flow hood. In this study, we investigated the IVF outcome of procedures carried out during 5 years of laboratory activity when a positive passive air sampling occurs under laminar flow hood in the absence of clear contamination in the embryo culture. We performed 570 air samplings, and we isolated at least 1 CFU of microorganisms in the TSA settle plate in 13 cases (2.28%). No infections were suspected in the culture media given the absence of detectable microorganisms under the microscope or a turbidity/color change of culture media visible to the naked eye (0% contamination rate). There were no statistically significant differences in biochemical pregnancy, live birth rate, and abortion between the "contaminated" Group P and the "negative" Group N. Surprisingly, we found a better outcome in terms of clinical pregnancy rate in Group P as compared to Group N, a finding likely due to the accidental lower age of Group P (p = 0.0133). Data showed that, in the absence of a detectable contamination in the embryo culture media, IVF cycles are safe when an air positive sample occurs in Grade A environment.