The share of births to unmarried women amounted to 20.2 percent of the 82,200 recorded in the country in 2012, the federal statistics office said in a report.
That is almost twice the rate in 2002 and marked the first time the 20 percent level had been surpassed, the report said.
By comparison, the rate of births to unmarried parents averaged 39.5 percent across Europe in 2011, the statistics office noted.
Switzerland’s overall birth rate rose 1.7 percent in 2012 from the previous year.
The statistics report highlights that women in Switzerland are continuing to have children for the first time at an older age, while those under the age of 30 are having fewer offspring.
The percentage of women over the age of 35 giving birth to newborns jumped to 30 percent last year from 22 percent in 2001.
Women are also waiting longer to have children, with the average age for giving birth for the first time rising to 30.4 years in 2012 from 28.9 years in 2001.