Definition - What does Culture Medium mean?
Culture medium is the solid, liquid, or semi-solid that embryos are grown in after fertilization. This medium supplies the nutrients and hormones, along with the proper environmental conditions, that the embryos need to grow and develop properly.
FertilitySmarts explains Culture Medium
After eggs are retrieved for in vitro fertilization (IVF), they are fertilized and placed in a culture medium to allow them to grow and develop. Because they are out of their natural environment, the embryos are very fragile and under stress, which can lead to lower rates of pregnancy and higher rates of miscarriage. It is crucial that the culture medium they are placed in supplies the necessary nutrients and mimics their natural environment as closely as possible.
Artificial culture medium is the most common medium used. This medium can either be the same throughout the embryo growth period or it can be a sequential system, where the embryos are moved to different media as they grow through different stages. This medium is effective in growing embryos to the blastocyst stage. The medium generally contains glucose, pyruvic acid, energy compounds, amino acids, nucleotides, vitamins, and cholesterol. The precise amounts of each nutrient are unique to each brand of culture medium commercially available. A study done in 2013 reviewed a wide range of commercial growth media and found that there isn’t a specific brand of medium that is better than any others on the market, in terms of pregnancies initiated.
Autologous endometrial co-culture is a second method of culture where a patient’s fertilized eggs are allowed to grow on top of a layer of her endometrial cells from her uterus. This method aims to create more natural physiological conditions to hopefully allow for a higher pregnancy rate from IVF.
A recently developed method places the embryos in a porous container and then places the container inside the patient’s uterus itself. The porosity of the container allows the uterine fluids to pass through inside and act as the culture medium.