Delayed childbearing: effects on fertility and the outcome of pregnancy.

In modern societies, the proportion of women who delay childbearing beyond the age of 35 years has greatly increased in recent decades. They are falsely reassured by popular beliefs that advances in new reproductive technologies can compensate for the age-related decline in fertility. Yet age remains the single most important determinant of male and female fertility, either natural or treated. The consequences of advancing maternal age are not only relevant for the risk of natural and assisted conception, but also for the outcome of pregnancy. Although the absolute rate of poor pregnancy outcomes may be low from an individual standpoint, the impact of delaying childbearing from a public health perspective cannot be overestimated and should be in the agenda of public health policies for the years to come. This review summarizes available evidence regarding the impact of delaying childbearing on fertility and pregnancy outcomes.