The following is a summary of “Minimized microbial contamination rate in conventional IVF cycles after modifications of cumulus–oocyte complex handling,” published in the June 2023 issue of Reproductive BioMedicine Online by Pingping et al.
Could the microbial contamination rate of oocytes and embryos in conventional IVF cycles be reduced further by modifying cumulus–oocyte complex (COC) handling procedures? Two changes were made to the COC management procedures. Since May 2018, a mark was placed on the outer wall of the 10-cm Petri dish to designate where the follicular fluid was poured out during the oocyte retrieval procedure (modified handling 1).
Since June 2019, a modified method of pipetting during denudation (modified taking 2) has been implemented. Before and after each modification, the rates of microbial contamination were compared. After incorporating the two changes in COC handling, the clinical outcomes of patients with a history or high risk of microbial contamination were reported. After implementing the first modification, the contamination rate dropped dramatically from 0.37 percent (9/2346) to 0.18 percent (2/1089).
After the second modification was implemented, no new contamination occurred in the 3178 conventional IVF cycles that followed (P = 0.001). In addition, no contamination was observed in patients with a history of microbial contamination or persistent candidal vaginitis during conventional IVF when COC handling was modified. Modifying COC handling procedures can reduce the microbial contamination rate in conventional IVF cycles. With current IVF techniques, the danger of contamination from the urogenital tracts may be less likely than previously believed.