In the movie Knocked Up, Seth Rogan’s character refers to the book What to Expect When You’re Expecting as “basically a giant list of things you can’t do.” It’s a line that pokes fun at the seemingly ever-expanding list of foods, behaviors and hazards that pregnant people are encouraged to avoid in order to reduce health risks to themselves and their babies.

Despite pre-natal education’s reputation for warning new mothers of every possible danger from jumping on trampolines to eating soft cheeses, contracting a vascular virus that increases risk of pre-eclampsia, pre-term birth, miscarriage and stillbirth is being ignored. Let’s look at the evidence.