Figure 4From: Demographic relevancy of increased use of assisted reproduction in European countries European countries by percentage of ART births and fertility postponement index, 2009. a Lesthaeghe & Niedert´s fertility postponement index (FPI) is the ratio of the sum of ASFR above age 29 to the sum of these rates between ages 20 and 29. Data sources: ESHRE, Eurostat, The Czech National ART Register. Back to article page