How to optimize culture media osmolality during Assisted Reproductive Technologies treatments

Area of Science:

• Reproductive biology andrology
• In vitro fertilization (IVF) techniques

Background:

• Maintaining stable osmolality in culture media is critical for human embryo development.
• Evaporation and incubator conditions can significantly alter media osmolality.

Purpose of the Study:

• To compare osmolality in sequential and single-step culture media.
• To evaluate the effect of mineral oil versus paraffin oil.
• To assess incubator humidity (dry vs. humid) on media osmolality during in vitro human embryo culture.

Main Methods:

• Prospective observational study involving 960 culture media droplets.
• Tested single-step and sequential media covered with mineral or paraffin oil.
• Incubation in both dry and humid incubators, with osmolality measurements on days 1, 3, 5, and 7.

Main Results:

• Osmolality increased significantly over time in dry incubators for both media types.
• Humid incubators maintained stable osmolality regardless of oil type.
• Single-step media in dry incubators showed higher osmolality with mineral oil compared to paraffin oil.

Conclusions:

• Humid incubators are superior for maintaining stable osmolality in embryo culture media.
• Paraffin oil offers better protection against evaporation for single-step media in dry incubator conditions.