We’ve already covered how egg freezing isn’t all it’s cracked up to be. But now science has a fertility clap back that we’re cautiously excited about: ovarian tissue freezing, an outpatient infertility treatment that removes and freezes ovarian tissue for later use.

It’s been considered experimental until now, but according to a new study, nearly four out of 10 (37.7%) women who undergo ovarian tissue freezing are able to have children later in life as a result. That’s nearly twice the success rate egg freezing has.

“Despite the clinical progress within the past two decades, the procedure still remains in the experimental realm,” wrote Drs. Fernanda Pacheco and Kutluk Oktay in the meta-analysis published in the journal Reproductive Sciences. “Given these recent data, ovarian tissue cryopreservation should be considered as a viable option for fertility preservation.”

To assess the state and success rate of this procedure, Dr. Kutluk Oktay, who performed the world’s first procedure of this kind in 1999, examined data from 1999 to 2016, together with his study co-author, Dr. Fernanda Pacheco. They found that:

• 309 ovarian tissue freezing procedures resulted in 84 births and 8 pregnancies that lasted beyond the first trimester.
  113 cases specified the women’s ages at the time when they froze their ovarian tissue; the women who conceived chose to freeze their ovarian tissue at age 27, on average.
• The procedure restored reproductive functions and reversed menopause in nearly two out of three women, including either a resumed menstrual cycle, ovarian follicular growth, or natural fertility.
• The procedure restored natural fertility in the majority of the cases: While two-thirds could conceive naturally only about one-third needed in vitro fertilization (IVF)

Not a wonder-cure yet for fertility issues — there are still a host of fertility barriers that this wouldn’t solve, including uterine or cervical inefficiency (i.e., structural problems that prevent a healthy fetus from being carried to term) and others not impacted by age —  but more promising than egg freezing (or even blood doping your way to pregnancy). At the very least, it’s a procedure to watch out for, as it moves from experimental to approved fertility treatment.