Coffee, Fats May Affect Fertility Treatment
High Coffee Intake, Some Fats May Lower Odds of IVF Success
Diet & IVF Success: Coffee Study
For the coffee study, Kesmodel evaluated nearly 4,000 cycles in women undergoing infertility treatments at a Denmark clinic.
At the start of the treatment and before each treatment cycle, the women reported how much coffee they drank per day. Kesmodel also took into account age, smoking, alcohol habits, weight, and other factors that may affect the success of fertility treatments.
Those who drank more than five cups of coffee a day cut their chances of achieving pregnancy.
"They have only half the chance of achieving pregnancy compared to women who do not drink coffee at all," Kesmodel tells WebMD.
The finding needs to be repeated in other studies, Kesmodel warns. But if the current study turns out to be valid, the effect of heavy coffee drinking on IVF success would be about the same as the known risk of smoking during IVF.
"I am not saying people [undergoing IVF] should not drink coffee at all," Kesmodel tells WebMD. "One or two cups a day would likely be okay."
He can't explain the link, and points out that he found evidence only of an association between heavy coffee drinking and odds of IVF success, not proof that coffee causes IVF failure.
Diet & IVF Success: Fats
In previous research, Chavarro and his team found links between trans fats and saturated fats and fertility problems.
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.