The figures from the National Institute of Statistics showed that the number of babies born in Spain last year was 6.1 percent down on the previous year.
But the stand-out figure was that births in Spain have dropped by an eye-opening 40.7 percent over the last decade, according to the study titled The Natural Movement of the Population.
In 2018 there were 369,302 babies born in Spain, some 23,879 fewer than in 2017.
In the same year there were 426,053 deaths recorded in Spain, which was a slight rise (0.4 percent) on 2017.
Those figures meant the Spanish population had dropped for the fourth consecutive quarter.
In other words Spain has 56,262 fewer citizens than it did 12 months ago.
The drop in the overall birthrate is partly explained by the fact that there are few children per mother and there are fewer mothers of child-bearing age than in the past.
In 2018 the average number of children per mother was 1.25 – the lowest since 2002 – compared to 1.87 children per woman in France, where the birth rate is also dropping.
Life expectancy however has increased to 83.2 years.
In terms of the number of marriages in Spain there was also a drop of 5.9 percent in 2018 compared to 2017.