Invocell performs slightly better than in vitro culture in blastocyst formation

Compared with in vitro culture, blastocyst formation from Invocell intravaginal culture performs slightly better, according to a study presented at the ASRM Scientific Congress & Expo.

However, the overall numbers of usable blastocysts, blastocyst development rate per inseminated oocytes and pregnancy outcomes are not significantly different, the researchers reported.

“Many IVF [in vitro fertilization] clinics want to set up their Invocell program for helping financial issues for patients, and some patients want to hold the device inside their body,” Taeshin Kim, PhD, TS(ABB), supervisor and embryologist at Carolina Conceptions in Raleigh, N.C., said during the presentation.

Carolina Conceptions began offering Invocell intravaginal culture as a treatment option in 2018, although the fertility clinic also provides conventional insemination with in vitro embryo culture to patients with more than 10 eggs retrieved due to the clinic’s lack of experience with intravaginal culture.

“Some research has compared Invocell and conventional IVF through the different cycles and different patients. But there is no reported difference between Invocell and conventional IVF on the same patient,” Kim said.

Nineteen patients had more than 10 eggs retrieved at the clinic between 2018 and 2020. Staff inseminated 10 oocytes with sperm and loaded them into the Invocell culture device, which was placed vaginally for 5 days. Also, staff inseminated and cultured surplus oocytes (average amount, 9.79 oocytes) following the clinic’s standard conventional IVF (cIVF) procedure. Staff then assessed embryos at day 5, transferred the best quality blastocyst, and froze surplus blastocysts.

In addition to pregnancy outcomes, the researchers analyzed blastocyst development and quality. They defined usable blastocysts as any blastocyst stage of at least 1 or 2 with a grade “B” inner cell mass (ICM) or trophectoderm. They also used Fisher’s Exact Test and T-test..

The researchers found no significant difference in the usable blastocyst rate per total number of inseminated oocytes between Invocell and cIVF (27.4% vs. 22%; P = .23). Also, significantly more best quality blastocysts were derived from Invocell (63.2%; n = 12) compared with cIVF (26.3%; n = 5; P = .022).

Though the difference was not significant, the researchers continued, the excellent ICM rate with grade “A” with Invocell was 28.8% (n = 15), while cIVF had a 14.6% rate (n = 6).

Finally, the clinic performed 15 embryo transfers from Invocell derived blastocysts and four from cIVF derived blastocysts, with no significant differences in pregnancy outcomes (11/15 for Invocell and 4/4 for cIVF). The ongoing pregnancy/live birth rate was 60% (n = 9) for Invocell and 50% (n = 2) for cIVF.

These findings suggest that Invocell intravaginal culture with conventional insemination works at least as well as cIVF, though a larger study with randomized allocation of sibling oocytes would be needed to determine superiority, the researchers said.