Coffee, Fats May Affect Fertility Treatment
High Coffee Intake, Some Fats May Lower Odds of IVF Success
Diet & IVF Success: Perspectives
No dietary advice changes should be based on the new research, experts who reviewed the findings agree.
"The coffee finding is not a shock," says Harry Lieman, MD, interim division director of reproductive endocrinology and infertility at Montefiore Medical Center/Albert Einstein College of Medicine in Bronx, N.Y.
In studies of women trying to conceive without IVF, he says, increased caffeine intake has been linked with an increased length of time to get pregnant.
He already tells his IVF patients not to drink more than two cups of coffee daily. "Now I have IVF evidence," he says.
The finding that women drinking five or more cups of coffee a day fared worse in IVF treatment may simply reflect other extreme habits, Paulson says.
"Anyone who drinks five cups of coffee a day probably has other habits that are not ideal," he suggests. "We cannot conclude from this study that coffee in and of itself interferes with having a good pregnancy outcome following IVF."
Paulson tells his IVF patients they can indulge in one cup of coffee a day, even if it is coffee-house coffee -- typically double the serving size at home.
"Drinking coffee in excess, based on this study, does seem to have a detrimental effect," says Peter Klatsky, MD, assistant professor of reproductive medicine at Montefiore Medical Center/Albert Einstein College of Medicine.
However, the findings may apply to a small percentage of patients, he says. "Most patients are not drinking five or more cups," he says.
The research on fat is too new to trigger diet advice changes, the experts agree.
Until more research is in, the experts who reviewed the findings suggest women undergoing IVF stick with the same guidelines as others. The Dietary Guidelines suggest keeping saturated fat intake low and total fat intake moderate.
This research was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.