I understand that pregnant women are not included in clinical trials and that might be the reason why the safety during pregnancy has not been assessed (the NHS explanantion in: http://www.nhs.uk/conditions/pregnancy-and-baby/pages/whooping-cough-vaccination-pregnant.aspx#patient ).
what I don't understand is why Sanofi writes:
"The use of this combined vaccine is not recommended during pregnancy"
It is the combined booster jab they give to pre schoolers it is not a live vaccine. The reason they say not recommended for pregnant women is to cover their backs as they have not been tested thoroughly enough for compliance to say 100% it is safe for pregnancy. It is not ethical to carry out a lot of clinical tests on pregnant women - you will see a lot of medicines are labelled as not suitable for pregnant women such as lemsip, buttercup syrup etc.
The vaccine is to you to help your immunity some people are concerned the baby will not get the benefits but the ideal solution is increasing your immunity will pass through the placenta - they don't think it will pass through breast milk - unless someone else has more recent updates on this.
If you are concerned talk to your nurse, doctor or midwife it is your choice another option would be to limit visitors when your baby is born.
I had the vaccine a few weeks ago after doing the research my Sisters in Law have never been vaccinated for anything so will be limiting visits and asking for them to wash hands etc as long as they are symptom free - this is what my nurse recommended when I got the vaccine.