Experts find recurrent miscarriage sufferers are ‘super-fertile’

Fertility experts based at Southampton’s teaching hospitals have discovered women who suffer recurrent miscarriages may actually be ‘super-fertile’. A study led by Professor Nick Macklon, a consultant in obstetrics and gynaecology at the Princess Anne Hospital in Southampton, found the problem – which affects around one in 100 women – occurs because they are too good at letting embryos implant in the uterus.
“In half of women who have recurrent miscarriages, we don’t know what the cause is, and many affected women feel guilty that they are simply rejecting their pregnancy,” said Prof Macklon, who is also director of the Complete Fertility Centre Southampton.
“But we have discovered it may not be because they cannot carry; it is because they may simply be super-fertile, as they allow embryos which would normally not survive to implant.’’
Prof Macklon and colleagues at University Medical Center Utrecht in the Netherlands compared cells from the lining of the wombs of women who have suffered recurrent miscarriage and those with normal fertility cycles.
They found cells from those with recurrent miscarriage move towards embryos, encouraging implantation regardless of quality, but those from normally fertile women were selective.
“Only around 30% of every 100 natural conceptions makes it to a baby and the rest are lost early in pregnancy. Mercifully, most women remain unaware of these losses because they happen before they miss their period,” he explained.
“When poorer embryos are allowed to implant, they may last long enough in cases of recurrent miscarriage to give a positive pregnancy test.”
Prof Macklon, who is chair of obstetrics and gynaecology at the University of Southampton, said the groundbreaking research, published in journal PLoS ONE, was a significant moment for sufferers.
“For the first time, women who have suffered with this extremely difficult problem can take some comfort by having a clearer understanding of the causes and realising they are not bad at carrying but perhaps too good.”
He added: “With much better understanding of how the female body selects – or doesn’t select – embryos, we hope to now explore ways we can fix this.”
Press release courtesy of Southampton General Hospital.