Fresh blastocyst transfer as a clinical approach to overcome the detrimental effect of progesterone elevation at hCG triggering: a strategy in the context of the Italian law

Abstract

Objective: To retrospectively evaluate whether fresh day-5 embryo transfer could overcomes the detrimental effect of subtle progesterone elevations at hCG administration on pregnancy outcomes in women undergoing ovarian hyperstimulation for IVF/ICSI cycles.

Study design: Retrospective study of 204 infertile patients aged 23-44 years who underwent IVF/ICSI treatment and fresh blastocyst transfer under the Italian law (embryos cryopreservation cannot be planned in advance). Women were divided into those with a progesterone level <1.5 ng/ml and those with a progesterone concentration ≥ 1.5 ng/ml at hCG triggering. The clinical pregnancy rate (CPR) after blastocyst transfer was the primary outcome.

Results: Age, body mass index (BMI), antral follicle count, anti-Mullerian hormone (AMH) and FSH values, mean number of stimulation days, ratio of GnRH agonist and antagonist cycles and total dose of gonadotrophins administered did not differ between the two groups. Serum estradiol and number of retrieved oocytes were significantly increased in the group with elevated progesterone and a significantly higher number of oocytes was used in this group. Fertilization rate, percentage of top quality embryos, and number of transferred blastocysts were similar in the two groups. The CPR was significantly higher in women with progesterone levels <1.5 ng/ml at hCG (50%) compared with women with progesterone concentration ≥ 1.5 ng/ml (33.3%) (odds ratio = 2.00, 95% confidence interval 1.07-3.75).

Conclusions: A fresh blastocyst transfer does not completely overcome the detrimental effect of progesterone rise at hCG on IVF/ICSI pregnancy outcomes.

Keywords: Assisted reproduction; Blastocyst; Clinical pregnancy rate; Ovarian stimulation; Progesterone.