Coffee, Fats May Affect Fertility Treatment
High Coffee Intake, Some Fats May Lower Odds of IVF Success
Diet & IVF Success: Fats continued...
In the new study, he evaluated 147 women having IVF at the Massachusetts General Hospital Fertility Center.
He grouped the women into categories depending on how much of three different kinds of fat they ate.
He also took into account their body mass index, smoking habits, and infertility diagnosis, all of which could affect their treatment.
- Women who ate the most saturated fats (found mostly in animal food sources) had fewer mature oocytes -- cells that form eggs.
- Women who ate the most polyunsaturated fats (found in plant-based foods and oils) had more poor-quality embryos than those who ate the least.
- Women who ate the most polyunsaturated fats also had a 12% higher proportion of cells in the embryo that were dividing more slowly than expected.
- Higher levels of monounsaturated fats (found in oils and many foods and found to improve cholesterol) increased the chances of a live birth after embryo transfer. Those who ate the most were about 3.5 times more likely to have a live birth than those who ate the least.
The amount of fats eaten varied. For instance, those in the lowest monounsaturated group ate about 9% of calories from this fat. Those in the highest group, about 25%.
Chavarro can't explain the links. "At this point it is not entirely clear what the underlying mechanisms explaining these associations might be," he tells WebMD.
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.