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Natural Versus Artificial Cycle for Frozen-Thawed Embryo Transfer

Frozen-thawed Embryo Transfer in a Natural Versus Artificial Cycle: a Randomized Clinical Trial

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03642665
Acronym
NAFT
Enrollment
554
Registered
2018-08-22
Start date
2018-09-25
Completion date
2024-11-01
Last updated
2025-02-28

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Embryo Transfer

Brief summary

This study evaluates clinical pregnancy rates, obstetrical outcome parameters, costs and patient preferences in natural cycle versus artificial cycle frozen embryo transfers (FET).

Detailed description

Transfer of cryopreserved embryos can be performed in a natural cycle (NC-FET) or in an artificially prepared cycle (AC-FET). Both cycle regimens have their advantages and disadvantages. So far, most comparative studies have failed to identify the optimal protocol for FET. In this study patients undergoing FET will be randomized between an endometrial preparation by a natural cycle or by an artificial cycle (by oestradiol validate and micronized progesterone).

Interventions

no medication

DRUGEstradiol Valerate

Oestradiol valerate (Progynova, Bayer, Germany) 6mg daily will be given from day 2 of the cycle. The dose of Progynova is increased to 8mg daily if the endometrial thickness is less than 7mm after 7-10 days of Progynova use. Progynova will be discontinued the day of the pregnancy test in case of a negative result. In case of a pregnancy, Progynova will be continued until 12 weeks or until diagnosis of a non-viable pregnancy.

DRUGMicronized progesterone

Micronized progesterone (Utrogestan, Besins, Belgium) 200 mg vaginally three times daily is started as soon as the endometrial thickness is 7 mm. Utrogestan will be discontinued the day of the pregnancy test in case of a negative result. In case of a pregnancy, Utrogestan will be continued until 12 weeks or until diagnosis of a non-viable pregnancy.

Sponsors

GZA Ziekenhuizen Campus Sint-Augustinus
CollaboratorOTHER
Imelda Hospital, Bonheiden
CollaboratorOTHER
Jessa Hospital
CollaboratorOTHER
Universitaire Ziekenhuizen KU Leuven
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

Multicenter prospective randomized clinical trial

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 45 Years
Healthy volunteers
No

Inclusion criteria

* Women undergoing FET after a first, second or third fresh IVF/ICSI cycle * Single embryo transfer (SET) or Double embryo transfer (DET) * Female age between 18-45 year * Women having a natural ovulatory cycle (24-35 days) * Normal uterine cavity (fundal indentation at the cavity \<10mm) * Written informed consent

Exclusion criteria

* Use of donor gametes * BMI \> or equal to 35 kg / m2 * Any contra-indication to estrogen or progesterone supplementation (e.g. history of thrombosis, prior or current hormone-sensitive malignancy…)

Design outcomes

Primary

MeasureTime frameDescription
Clinical pregnancy rate with fetal heart beat9 weeksClinical pregnancy rate with fetal heart beat diagnosed by ultrasound no later than the gestational age of 9 weeks

Secondary

MeasureTime frameDescription
Adverse events12 weekstombo-embolic events, serious side-effects (car leaflet) which require cancellation of treatment
Cycle cancellation rate4 weeks
Endometrial thickness3 weeks
Endometrial pattern3 weeksSonographic aspect of the endometrium (triple-line, no triple-line)
number of center visits to monitor FET cycleFrom date of randomization until the date of the embryo transfer or until cancellation (estimated period of time up to 4 weeks)
Multiple pregnancy rate9 weeks
Biochemical pregnancy rate9 weeks
Miscarriage rate12 weeks
Ectopic pregnancy rate9 weeks
Live birth rate41 weeks
patient satisfaction12 weeksTo evaluate the effect of the different regimens on patients wellbeing/distress, Patient Reported Experience Measures (PREMS) from validated questionnaires will be used. Twenty-two questions from the Benyamini questionnaire will be used (Benyamini et al. 2005) and 10 questions from the subscales 'environment' (α=0.81) and 'tolerability' (α=0.75) of the FertilQol questionnaire (Pedro et al 2013). On the day of embryo transfer, the treating gynecologist will hand out the questionnaire to the patient. The patient will return the filled-in questionnaire on the day of the pregnancy test, before she knows the result of the pregnancy test.
cost analysis per treatment cycleFrom date of randomization until the date of the embryo transfer or until cancellation (estimated period of time up to 4 weeks)

Countries

Belgium

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 20, 2026