Impact Of FET Preparation Protocol On Endometrial Peristalsis: A Prospective Cohort Study
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Endometrial peristalsis and hormone measurements.
- Who it may be relevant to
- Registry conditions: Infertility, Endometrial Peristalsis, Uterine Contraction, Endometrial Waves. Basic parameters: 18 years — 42 years · Female.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Vietnam
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Effects Of Endometrial Preparation Protocols On Peristalsis And Pregnancy Rates In Frozen Embryo Transfer: A Prospective Cohort Study
Overview
The uterus is a dynamic muscular organ that undergoes rhythmic, wave-like contractions known as endometrial peristalsis or endometrial waves. This muscular activity, which is an essential component of natural fertility, presents a nuanced and sometimes contradictory role in the context of assisted reproductive treatments. Endometrial peristalsis refers to the frequency, amplitude, and pattern of myometrial contractions occurring in different reproductive phases. These peristalsis play vital roles in sperm transport, embryo migration, and implantation. Clinical and imaging studies suggest that abnormal patterns or excessive contractility at the time of embryo transfer may disrupt endometrial-embryo synchrony, impair implantation, and increase miscarriage risk. However, most evidence on endometrial peristalsis pertains to fresh embryo transfer cycles, natural conceptions, or pathological contexts, such as adenomyosis or fibroids, with limited insights regarding its effects on different endometrial preparation protocols in frozen embryo transfer (FET). Understanding the dynamics of endometrial peristalsis in this context is clinically important, as inappropriate contractile activity could physically expel the embryo or create a non-receptive environment, ultimately reducing the chances of live birth. Despite its theoretical significance, there is a paucity of robust, prospective data correlating endometrial peristalsis patterns measured around the time of FET with different endometrial preparation protocols with subsequent pregnancy outcomes.
Detailed description
The uterus is a dynamic muscular organ that undergoes rhythmic, wave-like contractions known as endometrial peristalsis or endometrial waves. This muscular activity, which is an essential component of natural fertility, presents a nuanced and sometimes contradictory role in the context of assisted reproductive treatments. Endometrial peristalsis refers to the frequency, amplitude, and pattern of myometrial contractions occurring in different reproductive phases. These peristalsis play vital roles in sperm transport, embryo migration, and implantation.
Clinical and imaging studies suggest that abnormal patterns or excessive contractility at the time of embryo transfer may disrupt endometrial-embryo synchrony, impair implantation, and increase miscarriage risk. However, most evidence on uterine contractility pertains to fresh embryo transfer cycles, natural conceptions, or pathological contexts, such as adenomyosis or fibroids, with limited insights regarding its effects on different FET protocols. Several studies have demonstrated an inverse relationship between endometrial peristalsis and IVF success. Masroor et al. found that patients with lower endometrial peristaltic wave frequency (\<4 waves/min) before embryo transfer had significantly higher chances of clinical pregnancy and live birth compared to those with more frequent peristalsis. Similarly, Chung et al. reported that increased endometrial peristalsis frequency immediately after embryo transfer was linked to reduced live birth rates, suggesting that excessive motility may physically expel the embryo or disturb its implantation. In the prospective cohort study of 292 infertile women, Zhu et al. found that lower uterine peristaltic wave frequency (\<3.0 waves/min) before embryo transfer is associated with higher clinical pregnancy rates in both fresh and frozen-thawed embryo transfer cycles. In a study by Vuong et al. on patients with repeated implantation failure, they found that administering atosiban to patients with uterine peristalsis exceeding 16 waves per 4 minutes could improve pregnancy rates.
Different protocols for endometrial preparation in FET cycles, including natural cycles and hormone replacement therapy (HRT) cycles, create distinct hormonal environments that influence endometrial peristalsis and may impact pregnancy outcomes. Understanding how endometrial peristalsis varies by protocol and its effect on pregnancy outcomes is essential for optimizing IVF strategies.
Therefore, this study aims to evaluate endometrial peristalsis patterns in different FET protocols and their association with pregnancy outcomes.
Interventions
- Other Endometrial peristalsis and hormone measurements
Time point for measurement Endometrial peristalsis will be assessed at three specific time points: * On the second day to the fourth day of the menstrual cycle in the FET cycles. * The day of progesterone initiation or LH surge/hCG trigger, (before progesterone exposure) * On the day of embryo transfer, immediately prior to the procedure Hormone measurements Serum levels of estradiol (E2) and progesterone (P4) will be assessed three times, on the same days as the endometrial peristalsis meas
Primary outcome measures
- The frequency of endometrial peristalsis at different time points, and different FET protocol. [Time frame: • On the second day to the fourth day of the menstrual cycle in the FET cycles. • The day of progesterone initiation or LH surge/hCG trigger, (before progesterone exposure) • On the day of embryo transfer, immediately prior to the procedure]
Secondary outcome measures (12)
- Direction of peristalsis. [Time frame: • On the second day to the fourth day of the menstrual cycle in the FET cycles. • The day of progesterone initiation or LH surge/hCG trigger, (before progesterone exposure) • On the day of embryo transfer, immediately prior to the procedure]
- The association between endometrial peristalsis at different time points and pregnancy rates [Time frame: Up to delivery]
- The correlation between endometrial peristalsis at different time points [Time frame: • On the second day to the fourth day of the menstrual cycle in the FET cycles. • The day of progesterone initiation or LH surge/hCG trigger, (before progesterone exposure) • On the day of embryo transfer, immediately prior to the procedure]
- Live birth rates after the one embryo transfer. [Time frame: At delivery]
- Positive pregnancy test [Time frame: 10-14 days after embryo transfer]
- Clinical pregnancy [Time frame: 4-6 weeks after embryo transfer]
- Ongoing pregnancy [Time frame: 12 weeks of gestation or beyond]
- Implantation rate [Time frame: At 4-6 weeks after embryo transfer]
- Ectopic pregnancy [Time frame: Up to 12 weeks after embryo transfer]
- Miscarriage [Time frame: Up to 22 weeks of gestation]
- Multiple gestations [Time frame: At delivery]
- Multiple birth [Time frame: At delivery]
Eligibility criteria
Inclusion criteria
- Women aged 18 - 42 years old
- Scheduled for frozen embryo transfer cycles using hormone replacement therapy protocol or natural cycle protocol (True natural cycles or modified natural cycles)
- Transferred no more than two cleavage embryos or one good-quality blastocyst or no more than two poor-quality blastocysts
Exclusion criteria
- Having an allergy and contraindications for exogenous hormone administration (e.g., breast cancer, thromboembolic disease)
- Cycles with preimplantation genetic testing, oocyte donation, or in vitro maturation
- Having untreated uterine or adnexal abnormalities (e.g., intrauterine adhesions, unicornuate/ bicornuate/ arcuate uterus, endometrial polyp, large leiomyoma ≥5 cm in diameter, hydrosalpinx, endometrial hyperplasia).
- Use of uterine relaxants or intralipid infusion during the embryo transfer process.
- Use of a GnRH-agonist for downregulation within one month.
- PCOS patients
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
Vietnam · 2 centers
- My Duc Phu Nhuan Hospital — Ho Chi Minh City
- IVFMD Phu Nhuan - My Duc Phu Nhuan Hospital — Ho Chi Minh City
Identifiers
NCT: NCT07358468 · 18/25/DD-BVMD