Natural Versus HRT Cycles in Frozen Embryo Replacement Treatment

What Was Tested

In this phase 4 trial, researchers set out to test Nafarelin.

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).

It had two arms (groups): 1 (no intervention) and 2 (active comparator).

Natural FER (frozen embryo replacement).

HRT-FER (Down regulated frozen embryo replacement).

The registry classes the interventions as drug.

Who Took Part

Enrollment: 159 actual participants took part.

It was open to women only aged from 18 years up to 40 years.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: 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.

The full record lists 6 inclusion and 4 exclusion criteria; among the exclusions: 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).

How the Study Was Run

Design: randomized, parallel-group and open-label.

Because people in this Nafarelin study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Groups ran in parallel: each of the participants stayed in one arm throughout.

Nothing was hidden in this open-label Nafarelin study: the participants and staff both knew the treatment.

It started in 2009-11 with completion listed for 2013-05.

It ran at 2 sites in United Kingdom (2).

Its stated primary purpose is treatment.

What Was Measured

The main thing measured (primary outcome): The live birth rate in each group (time frame: 22 - 40 weeks following embryo transfer).

It also tracked 4 secondary outcomes, for example Clinical pregnancy rates (CPR), 3D endometrial volume and blood flow indices and Patient satisfaction with treatment.

What This Means in Plain Language

Put simply, this is a phase 4, randomized trial of Nafarelin in 159 people.

The trial is marked completed; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Nafarelin compound page, all human trials.