What effects does preeclampsia have on my baby?

Sometimes small, etc. Babies of women with preeclampsia might be smaller because they did not grow well (due to higher blood pressure) or were born early because the women needed to be delivered preterm. There are other possible effects that are known or being studied, but those are the main ones in developed nations.
Growth restriction. Pre-eclampsia (or "toxemia") can have multiple effects on pregnancy -- the high blood pressure can restrict blood flow to the placenta, causing growth restriction, premature labor, placental abruption (premature separation of the placenta form the uterine wall), and even more serious complications.