Post-warming culture and single vitrified-warmed blastocyst transfer with hyaluronic acid and prolactin: a randomized...

Does combined treatment with hyaluronic acid and prolactin (PRL) for post-warming culture and embryo transfer increase the live birth rate after single vitrified-warmed blastocyst transfer (SVBT)?

A three-arm, double-blind, randomized controlled trial (RCT) was conducted between October 2020 and May 2021. Overall, 1236 couples undergoing SVBT were randomized using a 1:1:1 ratio into three groups: after removing the zona pellucida, warmed blastocysts were incubated in a medium without hyaluronic acid or PRL (control group), a hyaluronic-acid-enriched transfer medium (EmbryoGlue group), or EmbryoGlue supplemented with PRL (EGP group) for 2-4 h prior to transfer in the same medium. The primary outcome was the live birth rate.

The live birth rate was higher in the EGP group compared with the control (OR 1.40; P = 0.0219) and EmbryoGlue (OR 1.38; P = 0.0266) groups. Although positive pregnancy and clinical pregnancy rates were comparable among the three groups, the ongoing pregnancy rate was higher in the EGP group compared with the control (P = 0.0142) and EmbryoGlue (P = 0.0249) groups. Furthermore, the rate of early pregnancy loss was lower in the EGP group compared with the control (P = 0.0073) and EmbryoGlue (P = 0.0053) groups. Subgroup analysis demonstrated significant interactions for embryo culture time (P = 0.0494) and serum progesterone (P = 0.0045): EGP treatment was effective for day 4-5 blastocysts and patients with insufficient serum progesterone.

This RCT suggests that combined treatment with hyaluronic acid and PRL is effective for improving the live birth rate in good-prognosis patients by reducing early pregnancy loss.