What if a quick, cheap and relatively painless procedure could double the chances of becoming pregnant through in-vitro fertilization? British researchers say a simple scratch to the uterine lining might do just that, but some experts are skeptical.
A new review of eight previously published studies suggests women who have their wombs gently scraped a month before starting IVF are twice as likely to having babies. The procedure, called local endometrial injury, takes about 15 minutes and costs as little as $200.
"Because the success rate of IVF is modest, these results are of considerable interest since the proposed intervention is neither expensive nor time-consuming and is apparently devoid of significant complications," the review authors wrote.
In IVF, a woman's eggs are plucked from her ovaries and fertilized in a laboratory. The resulting embryos are then transferred back into the woman's womb, but fewer than half will implant in the uterine lining and result in a pregnancy, according to the Society for Assisted Reproductive Technology.
"It's a very complicated biochemical process," said Dr. Richard Paulson, director of the Fertility Program at the University of Southern California's Keck School of Medicine in Los Angeles. "The embryo has to chemically communicate with the surface of the endometrium, give a kiss of death to some of the cells underneath to make room for implantation, and then invade the tissue much like a cancer."
The new review, published in the journal Reproductive BioMedicine Online, suggests a small scratch in the endometrium can boost the receptivity of the uterus to an implanted embryo. But some experts say the studies cited were flawed; most of them lacked proper control groups.
"Certainly this warrants revisiting the issue," said Dr. James Goldfarb, director of the University Hospitals Fertility Center in Cleveland and past president of the Society for Assisted Reproductive Technologies. "I think the value of this review is that it might entice people to do good randomized control studies so we can know if this truly helps or not."
The idea of scratching the womb to aid implantation stemmed from the observation in 2003 that women who had endometrial biopsies after one or more failed IVF cycles were more likely to get pregnant. But it's unclear how an endometrial injury might improve implantation. Some studies suggest the tiny scratch triggers the release of growth factors from the uterine lining. But the timing of it -- one month before a woman starts IVF -- raises questions.
"All those cells are going to be sloughed off," said Paulson, explaining how the uterine lining sheds with each menstrual period. "That's a problem."
The procedure, Paulson said, also defies Mother Nature.
"Teleologically, this would never have occurred in nature," he said of injuring an organ to boost its function. "You might be allowing the implantation of an embryo that would not normally implant."
But if endometrial injury is proven to safely promote implantation, it would be a welcome addition to a growing repertoire of fertility treatments. The simple procedure -- akin to an endometrial biopsy -- is fast, inexpensive and feels like little more than a menstrual cramp.
"A little plastic tube, about 3 millimeters wide, is pushed through the cervical canal," said Dr. James Grifo of the NYU Fertility Center in New York, describing the flexible catheter that gently scoops up some endometrial tissue. "It's certainly something worthy of more study."
For the women who have endured the emotional ups and downs of failed fertility treatments, the procedure raises hopes that fewer IVF attempts will fail.
"It's unbelievably frustrating," said Paulson. "It's the penultimate event in pregnancy… and we're unable at the present time to circumvent the physical problems that prevent it from happening."