The optimal progesterone level for performing cryotransfer (CT) remains under debate. The P level of 10 ng / mL produced by the corpus luteum in a natural cycle is usually a common reference value. Studies carried out in CT under artificial cycle (using both own and donor oocytes, or even with euploid embryos) have found worse rates of evolutionary pregnancy or live birth, as well as higher rates of abortion, when progesterone levels were low in the CT environment. This fact is significant if we consider that approximately one third of the patients who undergo a CT artificial cycle may find themselves in this situation.

For this reason, a group of researchers from Dexeus Mujer led by Dr Manuel Álvarez, conducted a prospective study on a total of 574 cycles (453 patients). The objective was to check whether the daily supplementary administration of progesterone injections by subcutaneous route in patients with a low serum progesterone level, starting treatment the day before the CT scan, and as a complement to the vaginal treatment with micronised P carried out up to that moment (200mg / 8 hours), could lead to an improvement in reproductive results, so that these were similar to those of patients who presented a progesterone level considered normal, of P >> 10.6 ng / mL.

Of the total, 342 were cycles in which the patients had adequate progesterone levels the day before the CT scan, and 226 were cycles in which low P levels had been recorded the day before the CT scan, but were compensated with the 25 mg progesterone supplementation, subdermally. In all cases, there was an euploid embryos transfer. The results of the study, recently published in the Human Reproduction, revealed that 98.2% of the patients reached P values >> 10.6 ng / mL on the day of the CT scan, and the birth rate was comparable in both groups: it reached 49.1 % in the cases in which the P level was normal vs 52.3% in the cycles in which the supplementation was administered.

Reference study:

Individualised luteal phase support in artificially prepared frozen embryo transfer cycles based on serum progesterone levels: a prospective cohort study
M. Alvarez, Sofía Gaggiotti-Marre, Francisca Martínez, Lluc Coll, Sandra García, I. González-Foruria, Ignacio Rodríguez, Mónica Parriego, Nikolaos P. Polyzos, and Buenaventura Coroleu
Hum Reprod. 2021 Mar 4; deab031. doi: 10.1093/humrep/deab031