title: Low-dosage clomiphene reduces premature ovulation rates and increases transfer rates in natural-cycle IVF.
abstract: Natural-cycle IVF has been suggested as an alternative IVF treatment. However, efficacy is limited due to high premature ovulation rates, resulting in low transfer rates. This study investigates whether low dosages of clomiphene citrate reduce premature ovulation rate and increase transfer rate. Of 112 women included (aged 35.2 ± 4.5 years) 108 underwent one natural-cycle IVF cycle with human chorionic gonadotrophin (HCG) to induce ovulation and 103 underwent one natural-cycle IVF cycle with 25 mg/day clomiphene from about day 7 until HCG administration. Before retrieval, 1.2 monitoring consultations per cycle were required. Clomiphene reduced premature ovulation rate, from 27.8% without to 6.8% with clomiphene (P < 0.001) and increased transfer rate from 39.8% to 54.4% (P = 0.039). Clinical pregnancy rates without and with clomiphene were 27.9% versus 25.0% per transfer and 11.1% versus 13.6% per initiated cycle. Use of clomiphene resulted in mild hot flushes and headache in 5% of patients. Nausea and persisting ovarian cyst formation was not observed. In conclusion, clomiphene citrate led to very few side effects, required 1.2 monitoring consultations, significantly reduced premature ovulation rate and significantly increased transfer rate per initiated cycle, an effect which was not age dependent.
authors.affiliation: University Women's Hospital, Division of Gynaecological Endocrinology and Reproductive Medicine, University of Berne, Effingerstrasse 102, 3010 Berne, Switzerland. Electronic address: michael.vonwolff@insel.ch.
authors.forename: M
authors.initials: M
authors.lastname: von Wolff
authors.affiliation: Centro Medico Puerta de Hierro, Boulevard Puerta de Hierro No.5150, Torre C, 5to Piso, Interior 503-C, Colonia Plaza Corporativa Zapopan, Zapopan, Jalsico, C.P. 45116, Mexico.
authors.forename: M
authors.initials: M
authors.lastname: Nitzschke
authors.affiliation: University Women's Hospital, Division of Gynaecological Endocrinology and Reproductive Medicine, University of Berne, Effingerstrasse 102, 3010 Berne, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Stute
authors.affiliation: Medizin and Service GmbH, Boettcherstrasse 10, 09117 Chemnitz, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Bitterlich
authors.affiliation: University Women's Hospital, Division of Gynaecological Endocrinology and Reproductive Medicine, University of Berne, Effingerstrasse 102, 3010 Berne, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Rohner
mesh_terms: D000293:Adolescent; D000328:Adult; D002996:Clomiphene / Q000008:administration & dosage / Q000494:pharmacology*; D004624:Embryo Transfer; D005260:Female; D005300:Fertility Agents, Female / Q000008:administration & dosage / Q000494:pharmacology*; D005307:Fertilization in Vitro; D006801:Humans; D010060:Ovulation / Q000187:drug effects*; D011247:Pregnancy; D018873:Pregnancy Rate; D055815:Young Adult
chemical_list: D005300:Fertility Agents, Female; D002996:Clomiphene
keywords: IVF; clomiphene citrate; natural cycle; ovulation