Efficacy of combined metformin-letrozole in comparison with metformin-clomiphene citrate in clomiphene-resistant infertile women with polycystic ovarian disease.

Abstract

BACKGROUND:

Adding metformin to clomiphene citrate in clomiphene-resistant polycystic ovary syndrome (PCOS) patients increases ovulatory response. However, because of anti-estrogenic effects of clomiphene it may be associated with lower pregnancy rate, offsetting the ovulation rate benefit. Letrozole is an aromatase inhibitor which induces ovulation without anti-estrogenic effects.

METHODS:

Infertile women with PCOS were randomly divided into metformin-letrozole (29 patients) and metformin-clomiphene groups (30 patients). After an initial 6-8 weeks of metformin, they received either letrozole (2.5 mg) or clomiphene (100 mg) from day 3-7 of their menstrual cycle. Estradiol (E2) levels, number of follicles, pregnancy rates and endometrial thickness were measured on the day of HCG administration.

RESULTS:

Mean total E2 and E2 per mature follicle were significantly higher in clomiphene group without a difference in mean number of mature follicles >18 mm and ovulation rate. Endometrial thickness was significantly higher in letrozole group. The pregnancy rate in letrozole group (10 patients, 34.50%) as compared with clomiphene group (5 patients, 16.67%) did not show significant difference, whereas full-term pregnancies were higher in letrozole group [10 patients (34.50%) versus 3 patients (10%)].

CONCLUSION:

In clomiphene-resistant PCOS patients, the combination of letrozole and metformin leads to higher full-term pregnancies.

• Authors: F Sohrabvand, Sh Ansari, M Bagheri
• Journal: Human reproduction (Oxford, England) (Hum Reprod) Vol. 21 Issue 6 Pg. 1432-5 (Jun 2006) ISSN: 0268-1161 [Print] England
• PMID: 16478764 (Publication Type: Comparative Study, Journal Article, Randomized Controlled Trial)

Chemical References

• Aromatase Inhibitors
• Fertility Agents, Female
• Hypoglycemic Agents
• Nitriles
• Triazoles
• Clomiphene
• Letrozole
• Metformin

Topics

• Adult
• Aromatase Inhibitors (administration & dosage)
• Clomiphene (administration & dosage)
• Drug Resistance
• Drug Therapy, Combination
• Endometrium (metabolism, pathology)
• Female
• Fertility Agents, Female (administration & dosage)
• Humans
• Hypoglycemic Agents (administration & dosage)
• Infertility, Female (drug therapy)
• Letrozole
• Metformin (administration & dosage)
• Nitriles (administration & dosage)
• Polycystic Ovary Syndrome (drug therapy)
• Pregnancy
• Single-Blind Method
• Triazoles (administration & dosage)