We know that most female mammals become sexually active at certain times during their cycle. When ovulating, they go into heat, which is a call to the males of the species, and mate. During other times, animals don't have sex. It is used for reproduction only. But humans are different, we engage in sex throughout our cycles and, because ovulation is invisible, we don't know when it is happening or whether it drives our sexual desires.
Previous studies on this didn't provide accurate results because while they looked at women's sex drives, they guessed at when ovulation occurred by counting days since the last menstrual cycle. Ovulation, however, can occur in a wide range, leaving the results questionable. Some studies show that sexual activity correlates with ovulation while others show sexual activity is consistent throughout a woman's cycle.
A new study used frequent ultrasounds to pinpoint ovulation in 1957 heterosexual women between the ages of 18 and 40. Women using hormonal birth control were excluded from the study. About three-fourths of the women were in relationships of six months or longer. All of the women agreed to keep a diary of all sexual activity and arousal for one month. The women received three transvaginal ultrasounds to pinpoint when ovulation occurred. Hormone levels were measured by three blood tests - pre-ovulation, around ovulation and post-ovulation.
The study found:
- Married women engaged in sexual activity (including masturbation) more often than single women: 1.9 times per week as compared to 1.5 times per week for single women.
- Women in a relationship were more likely to have sex on a weekend
- Single women engaged in sex around the time of ovulation more often
The researchers speculate that women in a relationship were more apt to take family or relationship considerations into account. Their sexual activity may revolve around "family management and leisure of both the woman and the partner's," explained one of the researchers, Salvatore Caruso at the University of Catania in Italy.
The single women in the study had more sex around the time of ovulation than the married women, suggesting that singles may be more influenced by hormones than the married women. This suggests that ovulation and hormones play a small role in sexual desire, however, other practical matters take precedence over hormones.
"Interested in Sex? Hormones May Have a Little to Say About That, Ladies." 2013, Nov 19, Stephanie Pappas, Live Science, NBCNews.com