Subfertility refers to a reduced level of fertility that may result in difficulty conceiving a child. It is often defined as the inability to conceive after one year of regular, unprotected intercourse. Subfertility can have various causes, including hormonal imbalances, anatomical issues, age-related decline in fertility, and lifestyle factors such as obesity or smoking. Research in the field of subfertility aims to identify the underlying causes of reduced fertility, develop effective diagnostic tools, and improve treatment options for individuals struggling to conceive. This research may involve studying the impact of genetics, environmental factors, and medical conditions on fertility, as well as investigating the efficacy of fertility treatments such as in vitro fertilization (IVF) or fertility drugs.