A prospective, randomised study to compare the effectiveness of the 24 hour versus 12 hour double doses regimen of levonorgestrel for emergency post-coital contraception

ISRCTN	ISRCTN06428555
DOI	https://doi.org/10.1186/ISRCTN06428555
Secondary identifying numbers	WHO/HRP ID 97137

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Not provided at time of registration

Prof Pak Chung Ho
Scientific

Department of Obstetrics and Gynaecology
Queen Mary Hospital
6F Professorial Block
Pokfulam Road
-
-
Hong Kong

Email	pcho@hkusub.hku.hk

Study design	Multicentre controlled randomised two-arm clinical trial
Primary study design	Interventional
Secondary study design	Randomised controlled trial
Study setting(s)	Hospital
Study type	Treatment
Scientific title
Study objectives	To compare the effectiveness of two double dose regimens of levonorgestrel (given at either 12 or 24 hour intervals) for emergency contraception. In addition, we studied the efficacy of both regimens when the coitus-treatment period was extended to 120 hours.
Ethics approval(s)	The Institutional Review Board (IRB) approved the study at each participating centre
Health condition(s) or problem(s) studied	Contraception
Intervention	1. Levonorgestrel two doses of 0.75 mg 12 hours apart 2. Levonorgestrel two doses of 0.75 mg 24 hours apart
Intervention type	Drug
Pharmaceutical study type(s)
Phase	Not Specified
Drug / device / biological / vaccine name(s)	Levonorgestrel
Primary outcome measure	Pregnancy rate
Secondary outcome measures	1. Delay in onset of next menses 2. Incidence of side-effects
Overall study start date	01/10/1998
Completion date	01/06/2003

Participant type(s)	Patient
Age group	Adult
Sex	Female
Target number of participants	2071 at five centres (Hong Kong, Shanghai, Nanjing, Shenzhen and Beijing)
Key inclusion criteria	1. Requesting emergency contraception within 120 hours of unprotected intercourse 2. Only one act of unprotected intercourse during current cycle 3. Willing to abstain from further acts during current cycle 4. Regular menstrual cycles (24 to 42 days) 5. Having at least one spontaneous cycle before current cycle 6. Available for follow-up in the next six weeks 7. Negative pregnancy test 8. Willing to participate 9. Not breastfeeding 10. No use of hormonal contraceptives or of rhythm or natural family planning method of contraception during current cycle 11. Not unsure about the date of last menstrual period
Key exclusion criteria	1. Post-abortion or post-partum patients whose period had not yet returned 2. Regular use of prescription drugs before admission to the study 3. Intercourse during the treatment cycle greater than 120 hours before admission into the study
Date of first enrolment	01/10/1998
Date of final enrolment	01/06/2003

Department of Obstetrics and Gynaecology

-
-
Hong Kong

World Health Organisation (WHO) (Switzerland)
Research organisation

20 Avenue Appia
Geneva
CH-1211
Switzerland

Website	http://www.who.int/en/
"ROR"	https://ror.org/01f80g185

Research council

Hong Kong Research Grant Council (Hong Kong) (ref: HKU7286/98M)

No information available

Intention to publish date
Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
Publication and dissemination plan	Not provided at time of registration
IPD sharing plan

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article	results	01/01/2005		Yes	No