Prospective observational comparison of arteria uterina blood flow between two frozen embryo transfer cycle regimens: natural cycle versus hormonal replacement cycle.

Purpose: Is there a difference in the blood flow of the Arteria uterina in frozen embryo transfer (FET) cycles between a Natural Cycle (NC) and a Hormonal Replacement Therapy (HRT) cycle?

Methods: Prospective observational study with measurement of the pulsatility index (PI) and resistance index (RI) throughout the ovarian stimulation cycle for IVF/ICSI, the FET cycle and at 12 weeks of gestation.

Results: A total of 124 ovarian stimulation cycles with preimplantation genetic testing for aneuploidy (PGT-A) and "freeze-all" strategy due to PGT-A were included. Mean patient's age was 31.

Reintroducing serum FSH measurement during ovarian stimulation for ART.

Research Question: What is the impact of systemic FSH concentrations during ovarian stimulation for IVF/intracytoplasmic sperm injection on systemic progesterone concentrations in the late follicular phase?

Design: Post-hoc analysis of a previously performed randomized controlled trial (RCT) performed between November 2017 and February 2020 in a tertiary IVF centre. The RCT included patients with infertility undergoing ovarian stimulation in a gonadotrophin-releasing hormone (GnRH) antagonist protocol. The GnRH antagonist was administered at 08:00 h and recombinant FSH at 20:00 h.

Step-Down of FSH- Dosage During Ovarian Stimulation - Basic Lessons to Be Learnt From a Randomized Controlled Trial.

A rise in serum progesterone in the late follicular phase is a well described adverse effect of ovarian stimulation for IVF/ICSI. Previous data suggest, that enhanced gonadotropin stimulation causes progesterone elevation and the incidence of premature progesterone elevation can be reduced by declining gonadotropin dosages. This randomized controlled trial (RCT) aimed to achieve a significant reduction of the progesterone level on the day of final oocyte maturation by a daily reduction of 12.