"Hitler's marriage-promotion policy had failed after five years of intensive propaganda backed by special laws and governmental regulations. Obviously, the economic basis was lacking. The earning capacity of the Germans under Nazi rule simply did not permit an increase in early marriages and the expansion of the family. In vain did the state use every means of economic pressure at its command: heavy taxation of bachelors, state wedding gifts, premiums for large families, awards to especially fecund mothers' employment privileges for married men and women. All to no avail... Hitler ordered the scientists of Germany into action. Psychologists, biologists, sexologists, and sociologists met to confer on the problem. A means had to be found to increase the birth rate substantially... The bachelor girlmust be brought to accept motherhood for the sake of the Vaterland."
A similar article can be read here.
Sex Under the Swastika