A new study suggests pregnant women may want to put down the bag of chips, walk away from those prepackaged snacks and put the tub of margarine back in the fridge if they don't want to birth bigger babies -- and that's especially true during the second trimester.

According to a study published in the upcoming November issue of The American Journal of Clinical Nutrition, pregnant women who consumed foods high in trans fats -- synthetic fats found in processed foods -- were more likely to give birth to bigger babies.