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Article: A randomized trial to compare 24 h versus 12 h double dose regimen of levonorgestrel for emergency contraception

TitleA randomized trial to compare 24 h versus 12 h double dose regimen of levonorgestrel for emergency contraception
Authors
KeywordsEmergency contraception
Levonorgestrel
Pregnancy
Randomized trial
Unprotected intercourse
Issue Date2005
PublisherOxford University Press. The Journal's web site is located at http://humrep.oxfordjournals.org/
Citation
Human Reproduction, 2005, v. 20 n. 1, p. 307-311 How to Cite?
AbstractBackground: Levonorgestrel (0.75 mg given for two doses 12 h apart) has been proven to be an effective regimen for emergency contraception when the first dose is given within 72 h of unprotected coitus. However, the dosing interval is inconvenient for those taking the first dose in the afternoon. We conducted a randomized study to evaluate two levonorgestrel dosing regimens for emergency contraception. Two doses of levonorgestrel 0.75 mg were administered with the first dose given up to 120 h after unprotected intercourse. The second dose was given 12 h later in the first regimen and 24 h later in the second regimen. Methods: We conducted a double-blind, randomized trial between 1997 and 2003 at five centres in China. A total of 2071 women requesting emergency contraception within 120 h of unprotected intercourse were recruited. They were randomized to receive two doses of 0.75 mg of levonorgestrel, given either 24 h apart or 12 h apart. Results: Outcome was unknown for 53 women (24 in the 24 h group and 29 in the 12 h group). Among the remaining 2018 women, the crude pregnancy rate was 1.9% in the 24 h group [95% confidence interval (CI) 1.17-2.94] and 2.0% in the 12 h group (95% CI 1.19-2.99). The proportion of pregnancies prevented was estimated to be 72% in the 24 h group and 75% in the 12 h group. Side-effects were mild in both groups. The efficacy of the 12 h regimen declined significantly when there were further acts of intercourse after treatment (5.0 versus 1.0%, P < 0.01). This was not observed in the 24 h group. Conclusions: Two doses of 0.75 mg levonorgestrel given either 24 or 12 h apart are effective for emergency contraception up to 120 h after unprotected intercourse. Further research to investigative more effective methods of emergency contraception is warranted. © European Society of Human Reproduction and Embryology 2004; all rights reserved.
Persistent Identifierhttp://hdl.handle.net/10722/87031
ISSN
2023 Impact Factor: 6.0
2023 SCImago Journal Rankings: 1.852
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorNgai, SWen_HK
dc.contributor.authorFan, Sen_HK
dc.contributor.authorLi, Sen_HK
dc.contributor.authorCheng, Len_HK
dc.contributor.authorDing, Jen_HK
dc.contributor.authorJing, Xen_HK
dc.contributor.authorNg, EHYen_HK
dc.contributor.authorHo, PCen_HK
dc.date.accessioned2010-09-06T09:24:25Z-
dc.date.available2010-09-06T09:24:25Z-
dc.date.issued2005en_HK
dc.identifier.citationHuman Reproduction, 2005, v. 20 n. 1, p. 307-311en_HK
dc.identifier.issn0268-1161en_HK
dc.identifier.urihttp://hdl.handle.net/10722/87031-
dc.description.abstractBackground: Levonorgestrel (0.75 mg given for two doses 12 h apart) has been proven to be an effective regimen for emergency contraception when the first dose is given within 72 h of unprotected coitus. However, the dosing interval is inconvenient for those taking the first dose in the afternoon. We conducted a randomized study to evaluate two levonorgestrel dosing regimens for emergency contraception. Two doses of levonorgestrel 0.75 mg were administered with the first dose given up to 120 h after unprotected intercourse. The second dose was given 12 h later in the first regimen and 24 h later in the second regimen. Methods: We conducted a double-blind, randomized trial between 1997 and 2003 at five centres in China. A total of 2071 women requesting emergency contraception within 120 h of unprotected intercourse were recruited. They were randomized to receive two doses of 0.75 mg of levonorgestrel, given either 24 h apart or 12 h apart. Results: Outcome was unknown for 53 women (24 in the 24 h group and 29 in the 12 h group). Among the remaining 2018 women, the crude pregnancy rate was 1.9% in the 24 h group [95% confidence interval (CI) 1.17-2.94] and 2.0% in the 12 h group (95% CI 1.19-2.99). The proportion of pregnancies prevented was estimated to be 72% in the 24 h group and 75% in the 12 h group. Side-effects were mild in both groups. The efficacy of the 12 h regimen declined significantly when there were further acts of intercourse after treatment (5.0 versus 1.0%, P < 0.01). This was not observed in the 24 h group. Conclusions: Two doses of 0.75 mg levonorgestrel given either 24 or 12 h apart are effective for emergency contraception up to 120 h after unprotected intercourse. Further research to investigative more effective methods of emergency contraception is warranted. © European Society of Human Reproduction and Embryology 2004; all rights reserved.en_HK
dc.languageengen_HK
dc.publisherOxford University Press. The Journal's web site is located at http://humrep.oxfordjournals.org/en_HK
dc.relation.ispartofHuman Reproductionen_HK
dc.rightsHuman Reproduction. Copyright © Oxford University Press.en_HK
dc.subjectEmergency contraceptionen_HK
dc.subjectLevonorgestrelen_HK
dc.subjectPregnancyen_HK
dc.subjectRandomized trialen_HK
dc.subjectUnprotected intercourseen_HK
dc.titleA randomized trial to compare 24 h versus 12 h double dose regimen of levonorgestrel for emergency contraceptionen_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=0268-1161&volume=20&issue=1&spage=307&epage=311&date=2004&atitle=A+randomized+trial+to+compare+24+h+versus+12+h+double+dose+regimen+of+levonorgestrel+for+emergency+contraception+en_HK
dc.identifier.emailNg, EHY:nghye@hkucc.hku.hken_HK
dc.identifier.emailHo, PC:pcho@hku.hken_HK
dc.identifier.authorityNg, EHY=rp00426en_HK
dc.identifier.authorityHo, PC=rp00325en_HK
dc.description.naturelink_to_OA_fulltext-
dc.identifier.doi10.1093/humrep/deh583en_HK
dc.identifier.pmid15567882-
dc.identifier.scopuseid_2-s2.0-12444295532en_HK
dc.identifier.hkuros99084en_HK
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-12444295532&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume20en_HK
dc.identifier.issue1en_HK
dc.identifier.spage307en_HK
dc.identifier.epage311en_HK
dc.identifier.isiWOS:000226199000044-
dc.publisher.placeUnited Kingdomen_HK
dc.identifier.scopusauthoridNgai, SW=7006074214en_HK
dc.identifier.scopusauthoridFan, S=11639038000en_HK
dc.identifier.scopusauthoridLi, S=36340268200en_HK
dc.identifier.scopusauthoridCheng, L=34869443100en_HK
dc.identifier.scopusauthoridDing, J=7402608672en_HK
dc.identifier.scopusauthoridJing, X=36339828800en_HK
dc.identifier.scopusauthoridNg, EHY=35238184300en_HK
dc.identifier.scopusauthoridHo, PC=7402211440en_HK
dc.identifier.citeulike75186-
dc.identifier.issnl0268-1161-

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