Clin Exp Reprod Med.  2020 Dec;47(4):284-292. 10.5653/cerm.2020.03552.

Effect of evaporation-induced osmotic changes in culture media in a dry-type incubator on clinical outcomes in in vitro fertilization-embryo transfer cycles

• Chi HJ
• Park JS
• Yoo CS
• Kwak SJ
• Son HJ
• Kim SG
• Sim CH
• Lee KH
• Koo DB

• KMID: 2509285
• DOI: http://doi.org/10.5653/cerm.2020.03552

Abstract

Objective
This study investigated whether adding outer-well medium to inhibit osmotic changes in culture media in a dry-type incubator improved the clinical outcomes of in vitro fertilization-embryo transfer (IVF-ET) cycles.
Methods
In culture dishes, the osmotic changes in media (20 µL)-covered oil with or without outer-well medium (humid or dry culture conditions, respectively) were compared after 3 days of incubation in a dry-type incubator. One-step (Origio) and G1/G2 (Vitrolife) media were used.
Results
The osmotic changes in the dry culture condition (308 mOsm) were higher than in the humid culture conditions (285–290 mOsm) after 3 days of incubation. In day 3 IVF-ET cycles, although the pregnancy rate did not significantly differ between the dry (46.2%) and humid culture (52.2%) groups, the rates of abortion and ongoing pregnancy were significantly better in the humid culture group (2.3% and 50.2%, respectively) than in the dry culture group (8.3% and 37.8%, respectively, p<0.05). In day 5 IVF-ET cycles, the abortion rate was significantly lower in the humid culture group (2.2%) than in the dry culture group (25.0%, p<0.01), but no statistically significant difference was observed in the rates of clinical and ongoing pregnancy between the dry (50% and 25.0%, respectively) and humid culture groups (59.5% and 57.3%, respectively) because of the small number of cycles.
Conclusion
Hyperosmotic changes in media occurred in a dry-type incubator by evaporation, although the medium was covered with oil. These osmotic changes were efficiently inhibited by supplementation of outer-well medium, which resulted in improved pregnancy outcomes.

Keyword

Clinical outcomes; Dry-type incubator; Evaporation; Osmotic change, Outer-well medium