Nav: Home

Contraception influences sexual desire in committed relationships

December 08, 2016

Sex is quite wonderful when the goal is to have children. But sex can also serve as a "glue" in a committed relationship.

Most animals have periods when they come into heat, and outside these periods they don't find sex interesting at all. Humans, however, are constantly interested in sex. This sex interest can seem like a waste of energy, but an evolutionary perspective may explain why we function this way.

MORE SEX WITH PROGESTERONE AND COMMITMENT

A new study from the Norwegian University of Science and Technology (NTNU) and the University of New Mexico confirm that sex is important for pair-bonding between men and women in relationships. The researchers also found a correlation between the type of oral contraceptive women use and how often couples have sex. The findings were recently published in the scientific journal Evolution & Human Behavior.

"The function of sex in humans outside ovulation is an evolutionary mystery. But we believe that it has to do with binding the parties in the relationship together," says Leif Edward Ottesen Kennair, a professor of psychology at NTNU.

Kennair worked with Trond Viggo Grøntvedt, Nick Grebe and University of New Mexico Professor Steve Gangestad to ask hundreds of Norwegian heterosexual women about contraception, sex and relationships.

Their results show that of women in long-term relationships and who are using hormonal contraception, those who are more committed to their relationships have more sex with partners, as one might expect.

"But this association was especially true when the contraceptive that women used had potent levels of synthetic hormones that mimic the effects of the natural hormone progesterone, and lower levels of the hormone estrogen," Gangestad said.

"We're talking about intercourse here, not other types of sex like oral sex, masturbation and such. This strengthens the idea that sex outside the ovulation phase has a function besides just pleasure," says Grøntvedt.

BIG DIFFERENCES BETWEEN TYPES OF CONTRACEPTIVES

Hormonal contraceptives, like birth control pills, implantable rods and patches, contain two types of hormones: estrogen, which naturally peaks just before ovulation when naturally cycling women can conceive offspring, and hormones that have the same effect as progesterone, which naturally peaks during the extended sexual phase, a time when offspring cannot be conceived. The levels of each hormone type vary in different contraceptives. Hence, some contraceptives mimic hormones that are more characteristic of ovulation, whereas others mimic hormones when women can't conceive. The women who used contraception with more estrogen were most sexually active when they were in a less committed relationship. On the other hand, women who used contraception with more progesterone were the most sexually active when they were faithful and loyal to their partners.

"Before we did this study, we didn't know how much difference there was between the two types of hormonal contraceptives," says Grøntvedt.

A CREDIBLE HOLISTIC PICTURE

The researchers surveyed two groups of women. All the women were using hormonal contraception and were in committed, heterosexual relationships. One group consisted of 112 women that researchers followed over a 12-week period. The women were asked how often and when in their cycle they had sex.

The second sample group consisted of 275 women in long-term relationships who used hormonal contraception. This group was not followed over time, but the researchers asked them how many times they had had sex in the past week. This type of study - using data collected at a specific point in time - is called a cross-sectional study. Both groups were asked to indicate the type of contraception they were using, and if a pill, which brand it was.

"Since we examined these two groups using different methods - a snapshot for the one group and a longitudinal study for the other - we can be confident that the results provide a reliable overall picture," says Dr Grøntvedt.

NATURAL OR SYNTHETIC HORMONES APPEARED TO BE THE SAME

The basis for the NTNU study was a 2013 American study, where 50 women and their partners answered a series of questions about their relationships, menstrual cycles and frequency of sex. None of these women were using any kind of hormonal contraception, so only their natural hormones were involved. The study showed that women initiated sex more in the extended sexual phase - when they were not ovulating and progesterone was the dominant hormone - if they were invested in the relationship.

NTNU researchers wanted to verify the American results in their study, but with participants who were using a hormonal contraceptive that simulates a natural cycle. Their results were the same as in the US study, in which women were not using any hormonal birth control.

The researchers were thus able to show that how often women have sex is linked to how committed they feel towards their partner and the type of hormone they are governed by, whether natural or synthetic.

"A lot of social psychology studies that have led to cool discoveries through the ages have lost status, because it hasn't been possible to copy them and verify the results. We are extremely pleased to have been able to verify the results of the study by Grebe and his colleagues, and we are equally pleased that we have also made new discoveries," Kennair says.
-end-
Reference: Trond Viggo Grøntvedt, Nicholas M. Grebe, Leif Edward Ottesen Kennair, Steven W. Gangestad. Estrogenic and Progestogenic Effects of Hormonal Contraceptives in Relation to Sexual Behavior: Insights into Extended Sexuality. Evolution and Human Behavior. Available online 2 November 2016. http://dx.doi.org/10.1016/j.evolhumbehav.2016.10.006

Norwegian University of Science and Technology

Related Estrogen Articles:

Placenta transit of an environmental estrogen
The human foetus is considered to be particularly sensitive to environmental contaminants.
Estrogen improves Parkinson's disease symptoms
Brain-selective estrogen treatment improves the symptoms of Parkinson's disease in male mice, according to new research published in JNeurosci.
The sneaky way estrogen drives brain metastasis in non-estrogen-dependent breast cancers
University of Colorado Cancer Center study shows that while estrogen doesn't directly affect triple-negative breast cancer cells, it can affect surrounding brain cells in ways that promote cancer cell migration and invasiveness
Estrogen made by neurons important to making memories
Estrogen in the brain is important to keep neurons communicating and memories being made, scientists report.
New study demonstrates effectiveness and safety of vaginal estrogen
Despite its proven effectiveness in treating the genital symptoms of menopause, low-dose vaginal estrogen therapy remains underused largely because of misperceptions regarding its safety.
More Estrogen News and Estrogen Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...