The California Department of Public Health has advised all Californian women of childbearing age get an injection of Tdap pertussis vaccine — before pregnancy if possible, but during or after pregnancy if not.
However Tdap — like all pertussis vaccines — has never been tested for safety during pregnancy. In fact, the vaccine product insert states that the vaccine is not indicated for pregnant women and has never been tested.
Writing in the Huffington Post, Dr. Bob Sears points out:
“At least there's no mercury in the Tdap vaccine! But still, we have absolutely NO indication that this vaccine is safe during pregnancy. Parents beware.”