Korean women in their 20s have an estimated 40 percent less sex than they did 10 years ago as more of them stay single until later in their lives.
According to a poll of 516 women by a team headed by Park Joo-hyun of Boramae Medical Center in Seoul, women in their 20s had sex just 3.52 times per month on average in 2014.
Women in their 30s had sex 4.18 times per month, compared to 5.31 times in 2004. But women in their 40s had sex 3.69 times a month, up from 3.22 times a decade earlier.
Researchers blame the increasing tendency of women to marry later in life for the decline in sex among women in their 20s. The average marrying age rose from 27.5 in 2004 to 29.6 in 2013.
"The frequency of sex increases with marriage, and the decline in the number of women tying the knot led to a drop in the number of times they had sex," a researcher said. Another factor, according to the researchers, is stress in a tough job market.
However, women have sex for the first time at a younger age, from 21.9 in 2004 dropping to 20.4 in 2014.
When it comes to birth control, an overwhelming 61.2 percent opted for withdrawal, while 20 percent chose to have sex only at certain times of the month and just 11 percent favored condoms and other contraceptives.
"Women are having sex for the first time at younger ages but are using risky types of contraception," Park said.