Fresh donor eggs have the edge over frozen eggs https://www.bionews.org.uk/page_147901

Scientists reverse fertility ageing in mice https://www.sciencedaily.com/releases/2020/02/200212103035.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Fhealth_medicine%2Fpregnancy_and_childbirth+%28Pregnancy+and+Childbirth+News+--+ScienceDaily%29