Nick Hardwick, the Chief Inspector of Prisons, said it was "simply not acceptable to initiate force for such purposes".
We were very concerned to find that force had been used to effect the removal of a pregnant woman, using non-approved techniques.
There is no safe way to do this while protecting the unborn child and it is simply not acceptable to initiate force for such purposes.
The pregnant woman's husband had been disruptive the night before his family's planned removal from the Cedars centre in Pease Pottage, West Sussex "shouting and kicking doors, causing some damage", the report found.
At one point it was judged that he had been trying to separate healthcare staff offering to examine his wife to take them hostage.
Staff were sufficiently concerned by his behaviour to take him to the 'cool down' separation room in full personal protection equipment before his removal.
Judith Dennis, of the Refugee Council, said the case was "shocking" and called for the UK Border Agency (UKBA) to heed the report's recommendations, which include that force should only ever be used against pregnant women and children "in order to prevent harm".
More top news
The Labour leader did not say whether he would maintain Britain's nuclear deterrent programme.
Ukip leader Paul Nuttall also said he would want to get rid of Sharia courts.
Over 40,000 people picked up their packs to take part in the annual marathon in the capital.