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Completed

NCT Number: NCT03642665

Natural Versus Artificial Cycle for Frozen-Thawed Embryo Transfer

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

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Key information

Conditions

Embryo Transfer

Age range

18 year–45 year

Sex eligibility

Female

Study type

Interventional

Phase

Phase 4

Primary location

UZ Leuven

Leuven, 3000, Belgium

About this study

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).

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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…)

Treatment and study plan

Natural cycle

Drug

no medication

estradiol valerate

Drug

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.

Other names: Artificial cycle

Micronized progesterone

Drug

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.

Other names: Artificial cycle

Primary outcomes

  1. Clinical pregnancy rate with fetal heart beat

    Time frame: 9 weeks

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

Secondary outcomes

  1. Biochemical pregnancy rate

    Time frame: 9 weeks

  2. Miscarriage rate

    Time frame: 12 weeks

  3. Ectopic pregnancy rate

    Time frame: 9 weeks

  4. Live birth rate

    Time frame: 41 weeks

  5. Multiple pregnancy rate

    Time frame: 9 weeks

  6. Adverse events

    Time frame: 12 weeks

    tombo-embolic events, serious side-effects (car leaflet) which require cancellation of treatment

  7. Cycle cancellation rate

    Time frame: 4 weeks

  8. Endometrial thickness

    Time frame: 3 weeks

  9. Endometrial pattern

    Time frame: 3 weeks

    Sonographic aspect of the endometrium (triple-line, no triple-line)

  10. number of center visits to monitor FET cycle

    Time frame: From date of randomization until the date of the embryo transfer or until cancellation (estimated period of time up to 4 weeks)

  11. cost analysis per treatment cycle

    Time frame: From date of randomization until the date of the embryo transfer or until cancellation (estimated period of time up to 4 weeks)

  12. patient satisfaction

    Time frame: 12 weeks

    To 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.

Sponsors and collaborators

Lead sponsor

Universitaire Ziekenhuizen KU Leuven

Other

Collaborators

  • GZA Ziekenhuizen Campus Sint-Augustinus
  • Imelda Hospital, Bonheiden
  • Jessa Hospital

Registry information

Official study title

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

Acronym: NAFT

Important dates

Study start
2018
Primary completion
2024
Study completion
2024
First posted
Aug 22, 2018
Registry last updated
Feb 28, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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