February 10, 2014 |
Infertility is among the most painful problems a couple can face, with emotional repercussions that can last for years—or a lifetime. The causes are often hard to pinpoint and it can be hard to treat.
Do women who take antidepressants have a harder time getting pregnant? Do men who carry their cell phones in their pants’ pockets have an increased risk of infertility?
Those are among the questions that researchers from the School of Public Health and the Slone Epidemiology Center are probing in the recently launched PRESTO(Pregnancy Study Online) project—the largest internet-based study of fertility in the United States.
The study—which has begun enrolling 2,500 women aged 21 to 45 (and, where possible, their male partners)—will rely on internet-based methods to recruit and follow participants with the aim of identifying lifestyle factors such as diet, exercise, and medication use that may affect fertility and pregnancy outcomes.
“The process of studying people via the internet is really still in its early days,” says lead investigator Lauren Wise, an SPH associate professor of epidemiology and a researcher at the Slone Epidemiology Center. Wise and colleagues are working on a similar internet-based study of over 8,500 women in Denmark, launched in 2007. Elizabeth Hatch, an SPH professor of epidemiology and a PRESTO coinvestigator, is the lead investigator of the Danish study.
“We’re testing several ideas here, including, will this kind of research method work in the United States?” Wise says. “If it does, we hope to break new ground in identifying factors associated with successful pregnancy— from soda consumption to antidepressant use to dietary choices. We have a lot of hypotheses from the Danish study that we want to explore.”
That study has already produced a number of findings, including that overexercising may make it harder for healthy-weight women to conceive, while moderate exercising is beneficial. The Danish study has also found that fertility peaks around age 30 for men and women, and declines slightly later than suggested in previous studies: women aged 35 to 40 had on average 23 percent less chance of conceiving in each menstrual cycle than women aged 20 to 24.
In 2012, fertility rates in the United States hit a record low for the second year in a row for women aged 15 to 44, in part because of a decline in the number of teenage pregnancies. In Massachusetts, the Department of Public Health reports that fertility rates are dropping and remain 16 percent below the national average.
An estimated 10 to 15 percent of American couples are affected by infertility, which is correlated with psychological stress and economic burden, among other factors. Infertility treatments, which include in vitro fertilization, can be expensive, invasive, and time-consuming.
The SPH researchers are trying to identify factors that improve fertility by casting a wide net that looks beyond age to factors such as menstrual cycle characteristics, lubricant use, consumption of caffeine and energy drinks, medication use, diet, and exercise.
“With women waiting longer to start a family, we really need to identify factors that lead to a successful pregnancy in older women—and we just don’t know enough yet,” Wise says. Coupled with the data from the Danish study, findings generated from PRESTO “could alter the ways in which researchers understand predictors of fertility—and also revolutionize the methods used to study epidemiology in the United States and globally,” she notes.
PRESTO participants—women actively trying to get pregnant without fertility treatments—are asked to complete one online questionnaire at enrollment and follow-up questionnaires every 2 months for up to 12 months or until pregnancy occurs. The follow-up questionnaires take about 10 to 15 minutes to complete. The women are asked to complete a dietary questionnaire (30 to 40 minutes) 10 days after the first questionnaire. Their male partners also are invited to enroll.
Among the new areas that PRESTO will explore is whether use of SSRIs (selective serotonin reuptake inhibitors), or antidepressants, impacts fertility among women. Men will be asked about such things as their bicycling habits and where they carry their phones.
The team also hopes to refine research findings from the Danish study on caffeine consumption. Although that study found that total caffeine intake was not related to fertility, soda consumption was associated with lower fertility and tea consumption with increased fertility.
The research team is partnering with the company that produces the web-based software program FertilityFriend.com, which allows women to chart menstrual cycles and record their fertility signs. Half of the PRESTO female participants will be randomly selected to receive a free premium subscription to FertilityFriend.com, in an effort to gauge whether participation in the web program has any influence on pregnancy outcomes.
In addition, researchers plan to track birth outcomes for study participants’ children who are born in Massachusetts through the state’s birth registry—affording new information on factors that may contribute to adverse outcomes.
Study coinvestigator Kenneth Rothman, an SPH professor of epidemiology, was one of the first US researchers to suggest using online methods to conduct research on fertility. He characterizes internet-based research as a new frontier for epidemiology that could prove more cost-effective and efficient than traditional methods.
Rothman says another strength of PRESTO is its inclusion of male partners. “While a woman is getting older and her fertility is declining, the same is happening to her partner. And the combined effect of aging for the couple can be quite noticeable,” he says. In the Danish study, “we estimated that a couple aged 40 might have half the prospect of having a baby with any given attempt than a similar couple at age 25 or so.”
PRESTO is actively seeking participants aged 21 to 45 who have recently started trying to conceive or plan to start trying within the next six months. The researchers are particularly interested in reaching minority participants.
Although the participation of male partners is optional, the study team is offering couples incentives for male participation, including a gift of one iPad mini for every 250 couples enrolled.
PRESTO is funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development(NICHD), part of the National Institutes of Health. Find more information on the study here or here.