I wouldn't do it! I'm sure you're going to get a ton of posts saying they ate peanut butter with no problems, so I'll give you the other side. Please, people, I'm asking you not to flame me for this. I'm not saying peanut butter is evil, I'm simply going to tell my own experience and feelings about this issue - an issue for me which is the absolute hardest thing I deal with in my life.
You are fortunate to have the info about peanut butter. When I was breastfeeding I was told nothing can pass through breast milk. I had difficulty getting my milk to come in, low milk-fat concentration, and a hard time eating enough calories during a difficult delivery and a serious infection. Peanut Butter was one of my recommended foods. Recommended by the OB, the Pediatrican, and the lactation specialist - so I took their advice. Looking back now on my screaming child who didn't want to nurse, was failing to thrive until we switched to formula, that now wears a Medic Alert and goes nowhere without his lifesaving epi-pen for his peanut allergies, I have to live with a lot of feelings of guilt. I know many other mothers of peanut allergic children who feel this same guilt.
Your child could be fine if you eat peanut butter, but if he turns out to be peanut allergic - you may find yourself questioning your decisions for many years.