Birth rates of 2.1 per woman are needed to keep population numbers constant. In Norway, the figure is now down to 1.71, having dropped every year since 2009.
The average age of first-time parents of both genders is also increasing, according to figures released by Statistics Norway.
Women that have a lot of children often find themselves defending their decision, consultant Dr. Anne Eskild told broadcaster NRK.
“When so many have no children or only one child, others have to have five children to keep numbers up,” said Eskild, who works a consultant at Akershus University Hospital and teaches at the University of Oslo.
The proportion of those having more children is also falling, however, according to the analysis.
Eskild said that working cultures in Norway are incompatible with large families, with ideals not recognising the value of having children.
“Today people have to defend themselves if they are full-time parents with many children. They face questions like ‘what is wrong with you, do you not know about family planning, why don't you have a job'”, she told NRK.
The trend of decreasing birth rates is not unique to Norway. Similar tendencies have been reported in Russia as well as in European countries such as France and Italy, although Norway's Scandinavian neighbour Denmark did report a slight improvement in 2015.
“It is not until after the age of 30 that there is enough economic security to have children, and then it becomes difficult to have many before biology sets its own limits,” Eskild said.
Many women in their 20s prefer to wait until they have finished studying and have stable, higher-paid jobs before starting families, the professor said.
“If you are not on the job market then you can be given 40,000-50,000 kroner ($4,700-5,800) [by the state] in social support, but others [who take maternal or paternal leave from well-paid jobs, ed.] can receive up to a million ($116,000). That is an unequal valuation of people's children, can lead to those who do not have access to those kinds of welfare systems choosing to delay having children or having abortions,” she said.
Former prime minister Kåre Willoch told NRK that he nevertheless saw the trend - and its association with families' economic situations - as a cause for concern.
“Families must have a satisfactory economy, and in all cases no worse a financial situation than those who have decided not to take on the task of providing for children,” he said.
Families “should be compensated with generous allowances, but instead these have been halved,” he said.