Delayed nidations, often referred to as implantation delay, is a term used in reproductive biology to describe the postponement of embryo attachment to the uterine wall. In scientific discussions, alternatives for delayed nidations can be expressed as delayed implantation or impaired uterine attachment. Delayed nidations can occur for various reasons such as hormonal imbalances, stress, or anatomical complications. In medical literature, it may also be mentioned under terms like delayed embryo implantation or retarded nidations. Regardless of the term used, this phenomenon can significantly affect fertility treatments, and understanding the underlying causes is crucial in addressing such issues for those trying to conceive.