Women are now having more sexual partners over a lifetime compared with 20 years ago and having sex 
earlier, according to a national UK survey.
However, one in ten women say that they have been forced to have sex against their will, compared to one in 71 men, and women who have had just one or two sexual partners are up to three times more likely than men with less than two partners to be infected with chlamydia, the Independent reports.
The survey [1], which was carried out between 2010 and 2012 and involved detailed interviews with more than 15,000 adults aged between 16 and 74 about their sexual behaviour and attitudes. It is the third such national sex survey.
“We do see a progressive decrease [in age] in the onset of sexual activity and at the same time we see an increase in the age of first cohabitation and of becoming a parent. Because those intervals have increased, the length of time the individuals are more at risk of adverse sexual health outcomes has increased,” Professor Kaye Wellings of the London School of Hygiene and Tropical Medicine, said.
“Women are more likely to have had a sexually transmitted infection and are obviously more likely to have an unplanned pregnancy,” she said.
Since the first study, there have been a number of emerging trends, notably a continuing decrease in the age at which both men and women start to have sex.
There is also a slight decrease in the frequency of sex, which has fallen to less than five times a month on average for both men and women compared with just over six times a month a decade ago.
In the 16-to-24 age group, about 31 per cent of men and 29 per cent of women report having sex before the age of 16 years, which is not significantly different from previous surveys. However, the increase in the number of sexual partners seen during the 1990s has levelled off for both men and women, Professor Wellings said.
“At the start of the 21st Century the picture is more complex. Generally it’s characterised by diversity. The trend towards increasing numbers of sexual partners has not continued for men [and] it has slowed for women,” she said.
Although more people are having sex earlier, the attitude of both men and women to extra-marital sex has hardened since 1990, with disapproval ratings increasing from 45 per cent to 63 per cent for men and from 53 per cent to 70 per cent for women.
Professor Dame Anne Johnson of University College London said: “We tend to think that these days we live in an increasingly sexually liberated society, but the truth is far more complex.”
Meanwhile, a recently published US study shows that teens and young adults who engage in frequent casual sex are at greater risk of depression and even suicidal thoughts.
A study published in the Journal of Sex found that poor mental health and casual sex contribute to each other over time among teens and young adults.
According to the research, carried out at Ohio State University, teens and young adults who had casual sex were more likely to be depressed later on.
The researchers also found teens who showed symptoms of being depressed were more likely than others to have casual sex.
The lead author of the study, Sara Sandberg-Thoma said that a question about whether casual sex caused depression, or whether people with depression tended to have more casual sex had always been present.
“This study provides evidence that poor mental health can lead to casual sex, but also that casual sex leads to additional declines in mental health” Sandberg Thoma said.