28 weeks is the beginning of the third trimester, and while its past the cusp of extra-utero survivability, but still young enough that some development normally still occurs, such as formation of pulmonary surfactant and the like. Teratogenic means literally, giving birth to a monstrosity, and in parlance means it can cause birth defects, such as the children born to mothers who took thalidomide being born with no arms, and babies born to mothers who came in contact with finasteride being born without genitals. At 28 weeks there's not any chance of not developing limbs or genitalia, but I imagine a teratogen could still cause you some problems in utero. From this article I found it says that after the embryonic stage at 9 weeks, "Teratogens taken during this period can result in improper organ functioning, delayed growth, but seldom result in birth defects"
I fully agree that if push comes to shove we need to focus on the mother's survival, but I'm still wondering if diverting to the ER round the bend couldn't provide us with better options. I doubt it. From my better understanding of how teratogens affect development, I think the risk is fairly low to the fetus at this stage, so I'd probably start the mag as soon as the seizure started, and if it was still going on after 5 minutes or drop some diazepam and cross my fingers. Here's a link to the article I got my information from, though I should warn you that there are some pictures of birth defects that might give you the willies:
http://wikis.lib.ncs...pment_in_Humans
I've dealt with one full blown eclampsia case in my career and it was a doozy. The venous pressure was so high it shot the IV catheter out and the blood spray looked like something from Saving Private Ryan, and no you wiseasses, it wasn't in an artery. We did the mag and benzo routine, we were able to control the seizures and get to a specialty hospital, but I never found out how the case turned out.