Dr. Charles J. Glueck, of Jewish Hospital Cholesterol Centre in Cincinnati, Ohio, and colleagues found a higher percentage of foetal loss among women who consumed higher levels of trans fatty acids.
Trans fatty acids, also known as trans fats, are common in processed foods that list partially hydrogenated oils as an ingredient.
Earlier studies have also found a relationship between a diet high in trans fatty acids and increased insulin resistance. This, in turn, increases the activity of plasminogen activator inhibitor, which has been associated with foetal loss.
To gain a better understanding of potential link between trans fatty acids and foetal loss, Glueck's group examined dietary trans fat intake among women involved in a childhood to adulthood survey of cardiovascular risk factors.
The team focused their investigation on 104 women who reported at least one pregnancy during 25 to 30 years of follow-up, Glueck and colleagues report in the medical journal Fertility and Sterility.
The investigators assessed trans fat intake when the women were 39,5 years old on average. Among these women, 57 percent reported no foetal loss, 24 percent reported one foetal loss, and the remaining women had two or more losses.
After categorising the study population according to average trans fat intake, the investigators found the rate of foetal loss increased from 30 percent among those with the lowest intake of trans fat in the diet (2,2 percent of total calories on average) to 52 percent among women with the highest intake of trans fat (defined as 4,7 percent of total calories).
As the percent of calories from trans fat increased, so did the risk of having one or more foetal losses, Glueck and colleagues report. This association was independent of body mass, insulin and glucose levels, and other factors potentially associated with risk for foetal loss.
Further research is necessary to confirm the association between foetal loss and trans fatty acid intake, but Glick and colleagues speculate limiting trans fats may be beneficial during pregnancy.
Current dietary recommendations suggest limiting trans fat intake to less than one percent of total calories, the researchers note.