Clinical trial NCT03581422: Natural Cycles With Spontaneous Versus Induced Ovulation in FET
Official title: Frozen-Thawed Embryo Transfers: a Comparison Between Natural Cycles With Spontaneous or Induced Ovulation
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Embryo Transfer
Lead sponsor: Istituto Clinico Humanitas
Sponsor class: OTHER
First posted: 2018-07-10
Enrollment: 2866
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: 2866 cycles were included in the analysis. To limit potential confounders, only single blastocyst transfer cycles were included, vitrified on Days 5 or 6, excluding PGT-a cycles and cleavage stage embryo transfers.

Brief summary: In recent years, frozen-thawed embryo transfer procedure (FET) has been widely used to increase the cumulative pregnancy rate per IVF-cycle: which is the best preparation protocol remains a matter of debate.

A retrospective analysis was conducted between 2012-2017. The aim was comparing clinical pregnancy rate (CPR) of pure natural cycle frozen-thawed embryo transfer (NC-FET) versus natural cycle frozen-thawed embryo transfer with hCG-triggered ovulation (mNC-FET).

Detailed description: Compared to repeated oocyte retrieval procedure, frozen-thawed embryo transfer (FET) has been widely used to increase the cumulative pregnancy rate per IVF-cycle, with demonstrated superiority in preventing ovarian hyperstimulation syndrome and improving cost-efficiency and time to pregnancy.

It is controversial whether triggering ovulation of the dominant follicle using human chorionic gonadotrophin (hCG) may benefit or reduce embryo implantation, when compared with a natural cycle environment. Unfavourable clinical outcomes of controlled ovarian stimulation have been reported by recently published studies, compared to the spontaneous LH surge.

This study aimed to compare the effectiveness in terms of better clinical pregnancy rates (CPR) of pure natural cycle frozen-thawed embryo transfer (NC-FET) versus natural cycle frozen-thawed embryo transfer modified by HCG administration\\with hCG-triggered ovulation (mNC-FET).

A retrospective analysis was conducted between 2012-2017. In patients with regular ovulatory cycles, the timing of embryo thawing and transferring was based on spontaneous LH surge (NC-FET). Patients attended for ultrasound evaluation of the dominant follicle from Day 8 to 10 of their menstrual cycle (depending on cycle length), detecting luteinizing hormone (LH) surge in urine/ taking an ovulation test for urinary LH measurement. In selected cases, a serum assays of LH, progesterone and estradioI has been further obtained. When the endometrial thickness reached 8 mm and dominant follicle 16-20 mm in diameter, hCG was administered in absence of urinary LH surge. Embryo thawing and transfer was planned 7 days after LH surge or HCG administration, whether G5 or G6 blastocyst. Exogenous progesterone supplementation started 2 days after hCG administration versus the same day of embryo transfer procedure in NC- ET. To limit potential confounders, only single blastocyst transfer cycles were included, vitrified on Days 5 or 6, excluding PGT-a (Pre Gestational Test for aneuploydia) cycles and cleavage stage embryo transfers. A unilevel and multi level logistic regression analysis was conducted using Stata Software versione15.

Eligibility criteria: Inclusion Criteria:

* only single blastocyst transfer cycles were included

Exclusion Criteria:

* PGT-a cycles and cleavage stage embryo transfers

Primary outcomes:
measure: CPR in NCFET vs mNCFET
timeFrame: 2012-2017
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
References:
citation: Levi Setti PE, Cirillo F, De Cesare R, Morenghi E, Canevisio V, Ronchetti C, Baggiani A, Smeraldi A, Albani E, Patrizio P. Seven Years of Vitrified Blastocyst Transfers: Comparison of 3 Preparation Protocols at a Single ART Center. Front Endocrinol (Lausanne). 2020 May 29;11:346. doi: 10.3389/fendo.2020.00346. eCollection 2020.