Feeling strange movements in her stomach, grandmother Debbie Amos felt certain they would stop, thinking the discomfort she felt was due to wind, however, she was proved to be wrong.

She was sure she was not pregnant as she underwent sterilisation 13-years ago, after giving birth to three children, two of them conceived with the help of fertility treatment.

But, that was in the summer, and this is now when at 43-years of age, Debbie became the proud though stunned mother of a fourth baby, after giving birth to her son, last week.

Cuddling her 'little miracle' baby Connor, a healthy 8lb 8oz., Debbie relates the shock that hit both her husband Melvyn, 57, and herself, when her test for those 'strange feelings' revealed her to be 6-months pregnant.

Doctors believe that her pregnancy probably occurred due to the fusing back of her fallopian tubes that had been clipped and cauterised during sterilisation. Debbie underwent sterilisation prevent another unplanned pregnancy, and thought it could never happen again, especially as it gets harder to conceive when one is older.

However, both Debbie and her husband are not going to sue the hospital, as they have been warned the procedure was not 100% effective. Even so, sterilisation is the most reliable form of contraception, with only one woman in 200 falling pregnant after the operation.