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Natural Versus HRT Cycles in Frozen Embryo Replacement Treatment

This study has been completed.
Oxford Fertility Unit
Information provided by (Responsible Party):
University of Oxford Identifier:
First received: February 12, 2009
Last updated: July 24, 2013
Last verified: July 2013

Frozen Embryo Replacement (FER)is a fertility treatment by which stored embryos from a fresh IVF treatment cycle are thawed and transferred into the uterus. Frozen embryos can be replaced either in the middle of a natural menstrual cycle (Natural FER) or in a cycle where the woman takes drugs to suppress her own hormones, and then takes Hormone Replacement Therapy (HRT) to prepare her uterus for the transfer of embryos(HRT − FER).

Both are widely used methods of fertility treatment. However, to date no well designed studies have been reported in which the two methods have been compared. This study aims to compare the two treatments in order to establish the best treatment protocol.

The study design is a single centre open randomized controlled trial funded by the Oxford Fertility Unit.

100 women who are considering FER treatment at the Oxford Fertility Unit and are eligible for the study will be recruited.

After giving their written consent they will be randomised to one of 2 groups: Natural FER and HRT FER.

Patients in both groups will be asked to attend one initial visit, which is additional to patients not taking part in the study.

Subsequent visits will depend on the treatment group but will not be additional for study participants. All visits requiring ultrasound will involve recording 3−D measurements, which increases the length of each visit by approximately 10 minutes. A patient satisfaction questionnaire would be completed at the end of the cycle.

A urinary pregnancy test is performed at home 2 weeks following the embryo transfer visit. If this is positive then further visits to the unit are arranged to confirm the clinical pregnancy.

Inclusion in the study would not increase the length of time of either treatment cycle. Follow up would extend to obtaining pregnancy outcome information.

Condition Intervention Phase
Drug: Nafarelin acetate, Oestradiol Valerate, Progesterone
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: A Randomised Controlled Trial of Natural Versus Hormone Replacement Therapy Cycles in Frozen Embryo Replacement IVF: a Pilot Study

Resource links provided by NLM:

Further study details as provided by University of Oxford:

Primary Outcome Measures:
  • The live birth rate in each group [ Time Frame: 22 - 40 weeks following embryo transfer ]

Secondary Outcome Measures:
  • Clinical pregnancy rates (CPR) [ Time Frame: 4 weeks after embryo transfer (at 6/40 pregnancy) ]
  • Implantation rate (defined as the number gestational sacs visible on ultrasound divided by the number of embryos replaced and expressed in percentage) [ Time Frame: 4 weeks following embryo transfer (6/40 pregnancy) ]
  • 3D endometrial volume and blood flow indices [ Time Frame: various from day 1 to embryo transfer ]
  • Patient satisfaction with treatment [ Time Frame: 4-10 weeks (at embryo transfer) ]

Enrollment: 159
Study Start Date: November 2009
Study Completion Date: May 2013
Primary Completion Date: May 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
No Intervention: 1
Natural FER (frozen embryo replacement)
Active Comparator: 2
HRT-FER (Down regulated frozen embryo replacement)
Drug: Nafarelin acetate, Oestradiol Valerate, Progesterone
Nafarelin acetate, Nasal spray, 400 mcg b.d., 4 weeks Oestradiol Valerate, tablet, 2mg o.d day 1-5, 2mg b.d. day 6-9, 2mg t.d.s day 10-13 (step-up protocol), 2mg q.d.s (if pregnancy confirmed, 4-10 weeks Progesterone, pessary, 200mg b.d. and t.d.s. (if pregnancy confirmed), 2-10 weeks
Other Name: Synarel,Progynova,Cyclogest


Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Women attending Oxford Fertility Unit planning a frozen embryo replacement cycle.
  • Willing and able to give informed consent for participation in the study.
  • Age at original fresh IVF cycle < 40 years old.
  • At least 3 embryos frozen in storage
  • First or second FER cycle
  • Regular ovulatory menstrual cycles, confirmed by luteal progesterone levels >16nmol/L and with cycle length < 35 days.

Exclusion Criteria:

  • Women with irregular cycles (outlined above), including amenorrhoea or oligomenorrhoea.
  • Co-existing medical illness including renal, cardiac and liver disease
  • Women for whom the study medication(s) are contraindicated or who have known allergic reactions to study medication(s)
  • Women who have already taken part in this trial (i.e. cannot have more than one treatment cycle as a participant in this trial)
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00843570

United Kingdom
Nuffield Department of Obstetrics and Gynaecology, University of Oxford
Oxford, Oxfordshire, United Kingdom, OX3 9DU
Oxford Fertility Unit
Oxford, Oxfordshire, United Kingdom, OX4 2HW
Sponsors and Collaborators
University of Oxford
Oxford Fertility Unit
Principal Investigator: Tim Child, MA MD MRCOG Nuffield Department of Obstetrics and Gynaecology, University of Oxford
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: University of Oxford Identifier: NCT00843570     History of Changes
Other Study ID Numbers: FER01
EudraCT 2009−009323−11
Study First Received: February 12, 2009
Last Updated: July 24, 2013

Keywords provided by University of Oxford:
Frozen Embryo Replacement

Additional relevant MeSH terms:
Genital Diseases, Male
Genital Diseases, Female
Estradiol valerate
Estradiol 3-benzoate
Estradiol 17 beta-cypionate
Polyestradiol phosphate
Contraceptive Agents
Reproductive Control Agents
Physiological Effects of Drugs
Hormones, Hormone Substitutes, and Hormone Antagonists
Contraceptive Agents, Female
Fertility Agents, Female
Fertility Agents processed this record on April 28, 2017