Effect of evaporation-induced osmotic changes in culture media in a dry-type incubator on clinical outcomes in in vitro fertilization-embryo transfer cycles
	    		
		   		
		   			
		   		
	    	
    	- Author:
	        		
		        		
		        		
			        		Hee-Jun CHI
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Jun-Sang PARK
			        		
			        		;
		        		
		        		
		        		
			        		Chang-Seok YOO
			        		
			        		;
		        		
		        		
		        		
			        		Su-Jin KWAK
			        		
			        		;
		        		
		        		
		        		
			        		Ho-Jeong SON
			        		
			        		;
		        		
		        		
		        		
			        		Seok-Gi KIM
			        		
			        		;
		        		
		        		
		        		
			        		Chae-Hee SIM
			        		
			        		;
		        		
		        		
		        		
			        		Kyeong-Ho LEE
			        		
			        		;
		        		
		        		
		        		
			        		Deog-Bon KOO
			        		
			        		
		        		
		        		
		        		
			        		
			        		Author Information
			        		
 - Publication Type:Original Article
 - From:Clinical and Experimental Reproductive Medicine 2020;47(4):284-292
 - CountryRepublic of Korea
 - Language:English
 - 
		        	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. 
            