Demographic age shift toward later conception results in an increased age in the subfertile population and an increased demand for medical care.

Objective: To investigate the effect of the nationwide age shift toward later conception on the corresponding subfertile population.

Design: Observational study.

Setting: General population, the Netherlands. Subfertile population, Maastricht University Medical Centre.

Patient(s): Women delivering their first child, women entering fertility care.

Intervention(s): Between 1985 and 2008 the age of women at their first visit to our fertility clinic was recorded prospectively. Data concerning the general population were extracted from the database of Statistics Netherlands.

Main Outcome Measure(s): Age shift in women's mean age at first fertility presentation; correlation age shift of general population and subfertile population; age-related ratio of number of women attending our fertility clinic compared with nationwide number of women delivering a first child.

Result(s): We found a 3.7-year increase in age at first fertility presentation during the study period. For each year of increase in age at first delivery we found a 1.10-year increase in age of women entering fertility care (R=0.93). The ratio between the number of new subfertility patients and the number of women delivering their first child stratified per age was calculated. With the ratio set to 1 at the age of 25 years, the ratio was 2.5 at age 35 years and 6.5 at age 40 years.

Conclusion(s): The demographic age shift toward later conception is accompanied by an increased age in the subfertile population and by an increased demand for medical care.