P-195 Euploid embryo transfer in a hyaluronic acid-enriched media results in a higher ongoing pregnancy rate than euploid embryo transfer in media not containing hyaluronic acid
Authors: Kamolakhon K , Kullyev A , Iunik T , Avdeichik S , Mirzalimova I , Ismailova Z , Temirgaliev A , Ganieva G , Abdurakhmanova S , Astapovich T , Umarova K , Kudratova D , Goikhman Y 
Published: July 2024

Abstract

Study question
Will using a hyaluronan-rich transfer medium increase the ongoing pregnancy rate and live birth rate when transferring euploid embryos cultivated in a dry incubator?

Summary answer
Transferring euploid embryos in a media with high concentrations of hyaluronic acid increases the ongoing pregnancy rate compared with media with no hyaluronic acid.

What is known already
Cochrane Review found that solutions with high concentrations of hyaluronic acid increase the chance of live birth by adding probably 1 additional live birth for every 14 embryos transferred in a high-concentration hyaluronic acid solution for patients aged 27 to 35. A study involving 85 frozen embryo transfer cycles showed a positive effect of high concentrations of hyaluronic acid on the results of transfer of morphologically poor euploid blastocysts.
Previous studies were conducted in humidified incubators where hyaluronic acid-rich media was equilibrated without oil overlay. Our clinic uses dry incubators, necessitating oil overlay with all media, including hyaluronic acid-rich media.

Study design, size, duration
A randomized prospective study involving 255 patients aged 19-44 undergoing a transfer of a single euploid embryo between June 2023 and November 2023.
Patients were randomly assigned to the study and control groups. Blastocysts were incubated after thawing for 3 hours either in a hyaluronic acid-enriched medium or in a medium without hyaluronic acid.

Participants/materials, setting, methods
Embryos underwent PGT-A at the blastocyst stage on either day 5 or day 6, using the EmbryoMap method. Trophectoderm biopsy was performed using the Flicking technique without a laser. 5-7 cells were removed for analysis. Blastocysts were vitrified following biopsy.
Hyaluronic acid-enriched media was equilibrated for 16-18 hours in a 5%O2 6%CO2 atmosphere in a well of 4-well culture dish under oil overlay (600 microliters of media and 500 microliters of oil).

Main results and the role of chance
In this ongoing study, 127 transfers of euploid blastocysts in a hyaluronic acid-rich media resulted in 70 ongoing pregnancies, with a 55.1% ongoing pregnancy rate. In comparison, 128 transfers of euploid blastocysts in a media with no hyaluronic acid resulted in 65 ongoing pregnancies, with a 50.8% ongoing pregnancy rate. The relative improvement in the ongoing pregnancy rate is 8.5%.
Our data suggests that using a hyaluronic acid-rich medium for the transfer of euploid blastocysts of good morphology can improve clinical pregnancy rates, although the effect is less dramatic than was shown in a 2023 study by Nakagawa et al. for morphologically poor euploid blastocysts, where more than twofold increase in clinical pregnancy rates was detected.

Limitations, reasons for caution
Specific media equilibration protocol is required for the incubation and transfer of embryos in a hyaluronan-rich transfer medium for IVF clinics utilizing dry incubators.
Further research is required to confirm results and to establish whether transferring embryos in hyaluronic acid-enriched media increases the live birth rate after euploid embryo transfer.

Wider implications of the findings
Our results show that it is feasible to use a hyaluronic acid-enriched medium in a dry incubator with an oil overlay and that using it according to described protocol could increase the ongoing pregnancy rate after a single euploid blastocyst transfer.

Trial registration number
not applicable