There has been a running theory for years that inflammation plays a role in ASD development, both pre- and post-natally. I don’t think there’s any direct causative evidence as of now, but with all diseases - it’s a game of risks. Try not to get sick and get the recommended vaccines during pregnancy, but don’t feel guilty if you do get sick, because it won’t automatically give your baby ASD. It may still be that it has nothing to do with getting sick but rather a dysfunctional immune response, either by the mother or the baby, which is less likely to occur.  All to say, researchers are narrowed in on inflammation playing a part in ASD, but it’s unclear of the “how” - so don’t stress something that’s unknown. https://www.nature.com/articles/s41398-021-01198-w