A woman in Japan with a medical condition that ought to prevent her from having children has given birth to a healthy baby boy through a cutting-edge fertility treatment called in vitro activation, or IVA.
The woman was one of 27 to try the experimental procedure, which was described in a study published online Monday by Proceedings of the National Academy of Sciences. Four other women were able to produce eggs after the IVA treatment, and one of them is currently pregnant, according to the PNAS report.
The patients in the study have a rare condition called primary ovarian insufficiency, or POI, which causes their ovaries to shut down prematurely and prevents their follicles from producing eggs. The condition, which is also known as premature ovarian failure, affects an estimate 1% of women of reproductive age.
"The only choice they have is to have egg donation or adoption," Aaron Hsueh, the study's senior author, explained in this video. "We're trying to figure a way that this patient can have their own mature eggs and then can have their own baby."
Eventually, the IVA approach could help women who are infertile due to sterilizing cancer treatments or who have become infertile after they reach middle age, said Hsueh, who studies molecular and cellular biology at Stanford University.
The key to the IVA treatment was finding a way to get immature follicles to grow to the point where they could produce a mature egg. Experiments in mice and rats led them to their formula, according to the researchers from Stanford and Japan who conducted the study.
The procedure begins with the removal of part of the ovary and "fragmenting" of the tissue. For this study, the researchers cut the ovarian tissue into small cubes that measured about 1 millimeter to 2 millimeters on a side. Cutting up the tissue disrupts a biological process that would normally put the brakes on tissue growth; without those brakes, the tissue is able to grow and proliferate.
The next step was to treat those cubes of ovarian tissue with a drug that was able to activate dormant follicles. After two days, the cubes were transplanted back into the patients, with the 13 eligible women getting from 40 to 80 pieces each.
Doctors in Japan monitored the women with ultrasounds and by checking for estrogen in their blood. They found that follicles were growing in eight of the 13 patients. These women went on to get treatments typically used for in vitro fertilization, culminating in egg retrieval. The doctors collected mature eggs from five of the women.
The patient who gave birth to a healthy baby boy had stopped getting her periods when she was just 25 years old. She was 29 when she started the IVA process, which produced six mature eggs. Those eggs were mixed with her husband's sperm to produce four embryos, two of which were transferred to her uterus. One of the embryos survived and was born 37 weeks and 2 days later. The baby boy weighed nearly 7 pounds, 3 ounces, and had Apgar scores of 9 and 10.
(In the photo above, the infant is held by Dr. Kazuhiro Kawamura, who worked in Hsueh's lab at Stanford 10 years ago and is now a physician at St. Marianna University School of Medicine in Kawasaki, Japan.)
Hers is the only success story – so far. Another patient had two embryos transferred and is currently pregnant. A third patient had two embryos tranferred but could not establish a pregnancy. Two other patients were able to create embryos, which are still frozen, according to the report.
Although cautioning that "more studies are needed to ensure the safety of the present IVA procedure," the researchers wrote that a refined version of this technique could theoretically help about 30% of women with POI – the ones who still have follicles that can be spurred to grow by following this recipe.
But they're not the only ones. In principle, this technique also should aid women who become sterile as a side effect of cancer treatments such as chemotherapy or radiation. Women in their early 40s who have trouble becoming pregnant on their own should also benefit from this approach, since they probably still have smaller follicles that can be prompted to grow, the researchers wrote.
"There will be further improvement of the process," Hsueh said. "Right now, we are just very lucky to have the initial advance. We hope the procedure will be used by many people."