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Letrozole Versus Mifepristone and Misoprostol in Silent Miscarriage

A Randomized Double-blind Placebo-controlled Trial Comparing Letrozole Versus Mifepristone As Pre-treatment Before Medical Management of First Trimester Silent Miscarriage Using Misoprostol

Status
Not yet recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06733727
Enrollment
884
Registered
2024-12-13
Start date
2024-12-06
Completion date
2028-06-05
Last updated
2024-12-13

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

Conditions

Silent Miscarriage

Keywords

silent miscarriage, mifepristone, misoprostol, letrozole

Brief summary

Management of first trimester silent miscarriage can be by expectant, medical or surgical management. Surgical management by suction evacuation is associated with surgical risks (including risks to the womb that can affect further pregnancy), anaesthetic risks and hospital stay. Medical management of first trimester silent miscarriage using misoprostol is another common option that can reduce the risk of bleeding and those associated with surgery. However, the current standard management of using misoprostol for the management of first trimester miscarriage only has a success rate of 70-80%, which is suboptimal. Recent large studies have shown that adding mifepristone pre-treatment before misoprostol in the management of silent miscarriage can improve the success rates of complete miscarriage after medical management. There are 2 problems with mifepristone. Firstly, it is not widely available in many countries for cultural and religious reasons because it is labelled as an 'abortifacient'. Secondly, it is expensive. One tablet of Mifepristone costs $500 HK dollars. There is a need to look for an alternative to mifepristone. Letrozole is an aromatase inhibitor which can reduce estrogen levels. Some studies have shown that it can improve the success rate of medical management of silent miscarriage and termination of pregnancy. It is safe, more widely available and cheaper than mifepristone. This is a randomized double blinded trial comparing the use of mifepristone versus letrozole as pre-treatment in the medical management of first trimester silent miscarriage using misoprostol.

Detailed description

This is a randomized double blinded trial comparing the use of mifepristone versus letrozole as pre-treatment in the medical management of first trimester silent miscarriage using misoprostol. Both groups will receive misoprostol (which is the standard management for medical management of silent miscarriage locally), but they will be randomized to either adding mifepristone or letrozole as pre-treatment. Mifepristone is usually taken once 2 days before misoprostol, whereas letrozole is taken 10mg daily for 3 days before misoprostol. Placebo of letrozole and mifepristone will be given to maintain double blindness of the groups.

Interventions

DRUGLetrozole

Letrozole pre-treatment in addition to misoprostol as medical management for silent miscarriage

DRUGMifepristone

Mifepristone pre-treatment in addition to misoprostol as medical management for silent miscarriage

Sponsors

Queen Mary Hospital, Hong Kong
CollaboratorOTHER
Pamela Youde Nethersole Eastern Hospital
CollaboratorOTHER
Kwong Wah Hospital
CollaboratorOTHER
Princess Margaret Hospital, Canada
CollaboratorOTHER
The University of Hong Kong
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

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

Inclusion criteria

* Diagnosed with silent miscarriage \<= 12 weeks of gestation by ultrasonography * Single intrauterine gestational sac * No heavy per-vaginal bleeding * No severe abdominal pain * No features of intrauterine infection * Able to understand the proposed research and able to comply with instructions * Having given voluntary written informed consent

Exclusion criteria

* Known allergy to mifepristone, misoprostol or letrozole * On drugs with potential drug interactions with mifepristone e.g. aspirin, clopidogrel, anti-coagulants etc. * Suspected ectopic or molar pregnancy or multiple pregnancy * Distorted uterine cavity by uterine septum or submucosal fibroids * Presence of intrauterine contraceptive device * History of bleeding tendencies e.g. haemorrhagic diseases, current anti-coagulant treatment * Previous history of retained products of gestation/ failed medical management of miscarriage * Opt for expectant or surgical management of miscarriage

Design outcomes

Primary

MeasureTime frameDescription
Gestational sac expulsion2 weeks, 30 daysGestational sac expulsion by the first follow up visit after 2 weeks of misoprostol administration and no additional surgical or medical intervention within 30 days after randomization

Secondary

MeasureTime frameDescription
Return of normal menses6 weeksReturn of normal menses without additional intervention
Requirement of repeated intervention6 weeksRequirement of repeated intervention including repeated course of medical treatment or surgery
Unplanned re-admission6 weeksNumber of unplanned re-admission
Analgesics6 weeksUse of analgesics
Time of tissue expulsion6 weeksTime of tissue expulsion
Vaginal bleeding6 weeksDuration and amount of vaginal bleeding
Complications6 weeksIncluding severe vaginal bleeding requiring transfusion, infection
Return of menstruation6 weeksTiming of return of menses
Women's satisfaction6 weeksClient satisfaction questionnaire
Side effects6 weeksVomiting

Contacts

Primary ContactJennifer Ko
jenko@hku.hk22554647

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026