The UK-Dutch study explained that wombs of certain women are too good at letting embryos implant, even those of poor quality which should be rejected.
Experts have welcomed the findings and hoped a test could be developed for identifying the condition in women.
Doctors at Princess Anne Hospital in Southampton and the University Medical Center Utrecht, took samples from the wombs of six women who had normal fertility and six who had had recurrent miscarriages.
High or low-quality embryos were placed in a channel created between two strips of the womb cells.
Cells from women with normal fertility started to grow and reach out towards the high-quality embryos. Poor-quality embryos were ignored.
However, the cells of women who had recurrent miscarriages started to grow towards both kinds of embryo.
"Many affected women feel guilty that they are simply rejecting their pregnancy," Prof Nick Macklon, consultant at the Princess Anne Hospital, said.
"But we have discovered it may not be because they cannot carry, [but] it is because they may simply be super-fertile, as they allow embryos which would normally not survive to implant," Macklon said.
"When poorer embryos are allowed to implant, they may last long enough in cases of recurrent miscarriage to give a positive pregnancy test," he added.
This theory still needs further testing and will not explain all miscarriages.
"This theory is really quite attractive. It is lovely. It's a really important paper that will change the way we think about implantation," Dr Siobhan Quenby, from the Royal College Obstetricians and Gynaecologists, told the BBC.
The study is published in the journal PLoS ONE.
