In the past 50 years the incidence of multiple pregnancies has increased dramatically due almost exclusively to two factors: delayed childbearing and assisted reproductive techniques. In this paper we analyze the variations in the incidence of multiple gestations in Andalusia, one of the biggest administrative regions in Spain, over the last decade. Assisted reproduction techniques are very often evaluated only in terms of implantation and pregnancy rates per cycle, ignoring everything related to complications of multiple births, prematurity or economic overload. The rate of twins in Andalusia has increased from 10.9 per thousand in 2000 to 16.2 per thousand in 2009. The rate of triplet births has also increased in recent years. After a decline in 2003, motivated by promulgation of the first Human Assisted Reproduction Law, there was an increase after a second law came into effect in 2006. Health care spending attributable to the excess of multiple pregnancies reported in the decade 2000-2010 may have been much higher than € 25 million.