The Home Office says police will give "due consideration" to pregnant women before using the 50,000 volt stun gun headed for the streets of Northern Ireland.
A medical committee's assessment of the use of Tasers on any individual concluded "that the risk of life-threatening and other serious injuries is considered to be low".
A Freedom of Information release by the Home Office indicated that conclusion was reached after computer modelling on possible effects Tasers may have "on the human body including a pregnant female".
As a result, guidance and training for police using the Taser was reviewed " to ensure due consideration is given to these individuals".
However, that guidance was found to be flawed when it was examined by the Northern Ireland Policing Board's human rights advisers earlier this year.
Its board's human rights lawyers, Keir Starmer QC and Jane Gordon, agreed Tasers could reduce the instances where police have to draw their guns.
But Mr Starmer said the PSNI and the Association of Chief Police Officers (ACPO) "hadn't put in place the necessary safeguards" for the use of Tasers. He said the PSNI should give specific examples of incidents where the weapons would be used.
ACPO guidance was the basis for the medical study referred to by the Home Office.
Mr Starmer said the standard for using Tasers should be "just below lethal force" - in situations where police consider that they will otherwise use firearms.
ACPO agreed to redraft their advice and the PSNI agreed to reconsider its policies before purchasing a dozen of the weapons for use in Northern Ireland.
Critics say the weapons have been linked to more than 100 deaths in the US and Canada, but police say Tasers are a good alternative to guns. They fire barbed electrodes at the target, which incapacitates them with high voltage jolts up to 21 feet away.
It has been approved for use by firearms officers in England and Wales since 2005, and the Home Office is planning to make them more widely available to police.
Chief Constable Sir Hugh Orde says he can go ahead with the Taser purchases without the board's approval, but would prefer to have their agreement.