Comparison of serum progesterone levels on the day of frozen embryo transfers according to type of endometrial preparation: a single centre, retrospective study.

The live birth rate following embryo transfer is comparable between spontaneous, stimulated and artificial cycles. However, the pregnancy loss rate appears elevated with hormonal therapy, possibly due to luteal insufficiency. This study aimed to determine whether the serum progesterone level on transfer day differed according to the endometrial preparation method for frozen embryo transfer (FET). Twenty spontaneous cycles (SC), 27 ovarian stimulation cycles (OS) and 65 artificial cycles (AC) were retrospectively studied from May to December 2019 in a single French hospital. The primary endpoint was the level of serum progesterone on the day of FET between the three endometrial preparation methods. The mean serum progesterone level on transfer day was 29.47 ng/ml in the OS group versus 20.03 ng/ml in the SC group and 14.32 ng/ml AC group (P < 0.0001). Progesterone levels remained significantly different after logistic regression on age and anti-Müllerian hormone (AMH) level. There was no significant difference in demographic and hormone characteristics (age, body mass index, embryo stage of embryo, type of infertility, basal follicle stimulating hormone, luteinizing hormone, estradiol and AMH levels), endometrial thickness, number and type of embryos transferred, duration of infertility, pregnancy rate, live birth rate and pregnancy loss rate. No difference was found in serum progesterone levels between clinical pregnancy with fetal heartbeat and no clinical pregnancy (no pregnancy or pregnancy loss, 17.49 ng/ml vs 20.83 ng/ml, respectively, P = 0.07). The lower serum progesterone level found on FET day in the AC group should be further investigated to see whether this difference has a clinical effect on the live birth rate.

[Impact of SARS-CoV-2 on fertility, gametes' quality and Assisted Reproduction Technology]. / Impact du SARS-CoV-2 sur la fertilité, les gamètes et l'Assistance médicale à la procréation.

The current pandemic context raises questions about COVID-19 consequences on Assisted Reproduction Technology (ART). Indeed, according to the first Biomedicine Agency recommendations, ART centers suspended their activities in March 2020 during the first wave of Covid-19. However, SARS-CoV-2 direct and indirect effects on gametes, fertility, pregnancy and neonatal health are still debated. The aim of this review is to assess the available data on this subject, to inform patients in care and adapt daily practice. Most recent studies are based on the effects of the infectious syndrome, on hormonal factors as well as on the expression of viral entry proteins (ACE2 and TMPRSS2) in cells involved in gametogenesis, to assess the impact of COVID-19. So far, no effect on female gametes was highlighted. More studies are needed to confirm this hypothesis. Mother to children transmission couldn't be proven, yet neonatal infection remains possible. However, men are more susceptible to be infected by SARS-CoV-2, to be symptomatic, and spermatogenesis is likely to be affected. Presence of the virus in semen is infrequently reported, but all of these parameters should be taken into account in ART.