Two new mothers are left battling infections after swabs were left inside them at maternity 'supercentre' Swabs left inside two women after they gave birth The 'Never Events' - deemed as those that should never happen - took place last year Both mothers suffered health problems as a result Two women had swabs left inside them after they gave birth at a maternity 'supercentre'. An investigation has been launched into the incidents at the Royal Bolton Hospital, Greater Manchester, between July and September last year. They both suffered health complications as the swabs became infected and had to be removed. Not so 'super': Two serious incidents at the maternity department of The Royal Bolton Hospital (pictured) are being investigated Both women had given birth at the Bolton NHS Foundation Trust maternity department, which was chosen to be a "supercentre" in the North West as part of Making it Better and has had £20 million invested in it over the past couple of years. Both women gave birth naturally, and afterwards, staff used swabs - a common procedure in cases where there has been tearing of the skin. A swab can be a cotton wool bud or a piece of gauze used to clean a wound or to apply pressure. But in both cases, the swabs were left inside the women. They have been described as 'Never Events', which means they should not take place if proper safety measures are implemented. Some common medical tools used during childbirth A spokesperson for Bolton Clinical Commissioning Group, said: 'The two Never Events reported in the January board relate to retained swabs after non-operative vaginal delivery where a non-operative invasive procedure was required to remove them and where there were complications to the patients arising from the swabs' continued presence. A Never Event is defined as a serious, largely preventable patient safety incident that should not occur if the available measures have been implemented. 'The NHS introduced this policy in 2009 following its proposal in 'High Quality Care for All', and it is designed to promote transparency and accountability when serious patient safety incidents occur. The Trust is undertaking thorough investigations in to these events. Heather Edwards, head of communications at Bolton NHS Foundation Trust, added: 'I can confirm that we did have these two incidents last year. We take any such event seriously. 'It wouldn't be appropriate to go into the details of these cases, however, thorough investigations of them were undertaken and the resulting detailed reports have been shared with the two women concerned.' The maternity unit at the Royal Bolton Hospital has approximately 6,600 births a year.