The number of German children under the age of five has risen by 1,700 over the past year, to 6,000, according to figures from the German Federal Office for Migration and Refugees.
That is the second highest number since 2008, and the second consecutive year of a surge in the number of under-5s.
The figures, compiled by the Federal Office of Migration and Refugee in response to a request by the German government, showed that there were 1,826,700 children under 5 in Germany last year, the highest level in more than four decades.
The figure rose to 1,862,000 in 2015.
That was followed by 1.071 million in 2014, and 1.034 million in 2013.
The number of infants under the care of the state has increased by almost 300,000 since 2008.
The numbers of the under-6s and the aged 65 and over have increased by more than the total population, which has increased more than 600,000 over the same period.
There were more than 1.5 million under-12s and 2.5 billion over-65s.
More children have been registered as refugees in Germany than in the past two decades, as the influx of refugees has become more difficult to control, the federal statistics office said.