This article originally appeared in the San Francisco Chronicle on February 5, 2014.
Nearly half of the 6.7 million annual pregnancies in the United States are unintended, according to a new Yale study, and the researchers’ survey of 1,000 women gives some clues about why. It seems there are quite a few misconceptions when it comes to conception.
For one thing, many women are unnecessarily concerned about infertility. In reality, the U.S. female infertility rate is between 6 and 15 percent, according to the study’s authors. But 40 percent of the women surveyed by Yale researchers said they would be worried about their ability to conceive if they were trying for pregnancy, and 20 percent said they would probably need infertility treatment. Authors cited other research showing more than a third of women with unintended pregnancies didn’t use birth control because they didn’t think they would get pregnant.
Survey respondents were ages 18 to 40 and their ethnicities and geographic locations were representative of the U.S. population. A large majority of them had the wrong idea about the most fertile times in their menstrual cycles. More than a quarter didn’t know that smoking, obesity, irregular cycles or sexually transmitted diseases could decrease the odds of getting pregnant, though most did know fertility declined with age. Researchers published these findings last week in the journal Fertility and Sterility.
These numbers show many women still have a lot to learn about eggs and sperm.
The percentage of women surveyed who thought that having sex more than once per day would increase the chances of becoming pregnant, though research doesn’t support this idea. The study points out that a man’s sperm count actually decreases if he ejaculates more than once a day.
The percentage of those surveyed who thought that certain sexual positions would make them more likely to conceive. Research doesn’t support that either. Regardless of the position, the study says, sperm reach the cervix within minutes.
The percentage of women who knew that to conceive, intercourse needs to happen before – not after – ovulation. The study notes that a woman’s “fertile window” is the six days leading up to and including the day of ovulation, and the chances of conceiving with intercourse after ovulation are slim.
The percentage of the surveyed women who either already had children or were pregnant at the time of the survey. Still, two-thirds of them answered the ovulation question incorrectly. Thus, the researchers say, many women get pregnant despite misunderstanding ovulation.