Frozen Embryo Transfer
Conditions
Keywords
Endometrial preparation, Natural cycle, Progesterone, Pregnancy
Brief summary
This study will assess the convenience of the natural proliferative phase frozen embryo transfer (NPP-FET) in terms of number of number of appointments needed before cycle scheduling.
Detailed description
Frozen embryo transfer (FET) is increasingly used nowadays in Assisted Reproductive Techniques (ART) clinics. Several factors account for this uprising. Among them, the concept of ovarian hyperstimulation syndrome (OHSS)-free clinic, the increasing use of preimplantation genetic testing (PGT), the improved vitrification systems, and the growing evidence regarding similar, or even better, pregnancy rates when FET are compared to fresh embryo transfers. In the last few years, research has focused on the selection of the best protocol for endometrial preparation in patients undergoing FET cycles. Despite the accumulating evidence suggesting similar reproductive outcomes following both artificial cycle (AC-FET) and natural cycle (NC-FET) protocols, AC-FET is frequently adopted in ART centers due to its convenience in terms of cycle scheduling. However, a role for the corpus luteum in the maternal vasodilatory changes of early pregnancy has recently been associated with a decreased risk of pre-eclampsia. In fact, several large cohort studies have reported a higher risk of hypertensive diseases of pregnancy, macrosomia, post-term delivery and cesarean section following AC-FET. The NPP-FET protocol is a strategy that potentially allows for cycle scheduling while maintaining the benefits of the natural cycle in terms of pregnancy outcomes. The main goal of the present study is to analyze its convenience in terms of the number of appointments needed before FET scheduling by comparing it with the NC-FET protocol. Additionally, the investigators aim to compare the reproductive outcomes between the two strategies and to analyze whether NPP-FET patients undergo ovulation. Briefly, the study group will prospectively recruit ovulatory patients who will perform vaginal ultrasound monitoring will be performed on cycle day 8-12, depending on the length of the patients' menstrual cycle. When the endometrial thickness is at least 7 mm and the dominant follicle is at least 13 mm, vaginal micronized progesterone will be initiated at 400mg every 12 hours. One embryo will be transferred on the fifth day of progesterone supplementation under ultrasound guidance. The control group will include a retrospective cohort of ovulatory patients who underwent NC-FET.
Interventions
When endometrial thickness is above 7 mm, vaginal micronized progesterone will be administered 400mg 12/12h when the dominant follicle is at least 13 mm, serum estradiol (E2) levels are \>80 pg/ml, and serum progesterone levels are \<1.5ng/ml. Embryo transfer will be performed on the fifth day of progesterone.
Sponsors
Study design
Eligibility
Inclusion criteria
* Endometrial thickness ≥ 7 mm on the day of starting progesterone-based luteal phase support (LPS) * Serum progesterone levels \<1.5 ng/ml on the day of starting progesterone-based LPS * LPS with micronized progesterone 400mg b.i.d. * Regular cycles (\>24 days, ≤ 38 days) * IVF/ICSI with donated oocytes * Single blastocyst stage embryo transfer * First or second embryo transfer from the same cohort
Exclusion criteria
* Use of exogenous ovarian stimulation during FET * Untreated hydrosalpinx, polyp, submucous myomas or severe adenomyosis * Recurrent pregnancy loss (≥ 3 previous pregnancy losses) * Recurrent implantation failure with embryos from oocyte donation (≥ 3 previous failed embryo transfers) * Personalized initiation of exogenous progesterone according to a previous endometrial receptivity assay test
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of appointments needed before cycle scheduling | Up to three weeks | Number of visits for cycle monitoring until embryo transfer scheduling |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cycle duration until embryo transfer (days) | Up to four weeks | Number of days since the first day of menstrual bleeding until the day of embryo transfer |
| Proportion of patients with low progesterone values on the day of embryo transfer | One day | Percentage of patients with low serum progesterone levels on the day of embryo transfer |
| Human corionic gonadotropin (hCG) positive rate | 10-14 days after ET | Proportion of patients with a positive hCG test |
| Miscarriage rate | Up to 20 weeks after ET | Proportion of patients with spontaneous loss of an intra-uterine pregnancy prior to 22 completed weeks of gestational age |
| Ongoing pregnancy rate | 9-11 weeks after ET | Proportion of patients with a pregnancy beyond the 11th week |
| Live birth rate | 40 weeks after ET | Proportion of patients with a live birth |
Countries
Portugal
Contacts
Instutito Valenciano de Infertilidade de Lisboa (IVI-RMA Lisboa)