When Emma Power fell pregnant with twins whilst she was taking the contraceptive pill she didn't want to take a chance again.
So she changed her method of contraception, opting for the contraceptive implant instead - but amazingly fell pregnant with her SECOND set of twins whilst using the implant.
Mrs Power and her husband John have been branded as 'super-fertile' by doctors who have now sterilised her AND given him a vasectomy as they said it was likely the couple would fall pregnant again with yet another multiple birth.
Mrs Power, 30, who lives in York with husband John, 31, said: 'It's unusual to fall pregnant with one set of twins whilst on the pill, but to fall pregnant with yet another set whilst I was on the implant is just unbelievable.
'The doctors suggested that I was sterilised and John to have a vasectomy too, so that there was no chance of me falling pregnant again.
'They said that I must be incredibly fertile and if we just relied on contraceptives again, then I was likely to fall pregnant with yet another multiple birth - and we couldn't risk having yet another set of twins!'
Mrs Power, who met her husband whilst studying at college, discovered she was pregnant at 19 despite being on the contraceptive pill.
She said: 'It was a complete surprise when I found out I was pregnant. I had been taking the pill for a while and thought there was no way that I could possibly fall pregnant. I made sure I took it each day, and I hadn't been ill.
'So to find out I was pregnant was a complete shock. When I went for my scan and I was lying on the scanning table and the sonographer told me that she could see two heartbeats. I couldn't believe what I was hearing - that I'd fallen pregnant with twins whilst I was on the pill.'
Mrs Power gave birth to twins Connor and Kyle, now ten, by caesarian operation at York Hospital when she was 37 weeks pregnant, after developing the potentially life threatening condition pre-eclampsia.
Afterwards she decided to change her contraceptive method to the implant instead. She said: 'I'd fallen pregnant once whilst I was taking the pill, so I couldn't risk it happening again. So I changed to the implant instead.'
Five years later she started feeling unwell and decided to take a pregnancy test. It was a positive - meaning that she had fallen pregnant despite being on the contraceptive implant.
She said: 'We had just recently watched the film 'Twins' with Arnold Schwarzenegger so we joked about me being pregnant with twins again. But I thought it was going to be impossible. What mum could possibly have fallen pregnant with twins twice - both times whilst taking contraception.'
But when Mrs Power went for a scan, she was in for a double shock. The songrapher yet again discovered two heartbeats.
She said: 'I'd had some bleeding, so I wasn't sure whether the sonographer was going to find a heartbeat at all. So when she said there were two again in there, it was such a relief, but such a shock again too.
'I'd come for the scan on my own, so I called John and asked him if he was sitting down before I broke the news to him. He didn't believe me until I actually showed him the scan photo with two heartbeats on.'
Mrs Power gave birth to her twin daughters Jessica and Ruby, now four, by caesarian, and during the operation, doctors also sterilised her. They recommended that Mr Power also have a vasectomy operation too, which was carried out several months later.
She said: 'Doctors said I must produce at least two eggs every time I ovulated each month, so there was a high risk of me falling pregnant with multiples again.
'They said that after my fallopian tubes had been cut and tied, there was a small risk of them mending themselves again, so they advised that John have a vasectomy operation too, just to be on the safe side.
'I do feel very lucky to have my two sets of twins - even if they weren't planned and were a complete surprise.'
The likelihood of her having two sets of non identical twins whilst using these contraceptive methods is one in three billion.
A spokeswoman for the Multiple Births Foundation in London said: 'We have never heard of this happening before.'
This article originally appeared on that's life!