A concept of early ovarian ageing has been advanced. This theory suggests that some women will experience problems of fecundity at an early age given that the age of menopause is earlier for some women, and there is a fixed time of accelerated atresia leading up to menopause. Various components of this theory are examined based on existing literature. While the theory has merit, and is important to consider in terms of reproductive health, it remains a hypothesis. It is also plausible to consider that a segment of the population will have later ovarian ageing in that menopause can be as late as 58 years for some women. Further, it is not known whether there really is a fixed time of accelerated atresia leading up to menopause in all women. The practical considerations dealing with this hypothetical concern also are not trivial. How will certain women with early ovarian ageing be identified, what hormonal and other factors should be measured, and what advice is reasonable for these young women?