From the Guidelines
Metformin for Infertility
Metformin is not recommended as a first-line treatment for infertility in women with polycystic ovary syndrome (PCOS) due to limited evidence on its effectiveness in improving pregnancy outcomes 1.
Key Points
- The American College of Obstetricians and Gynecologists (ACOG) recommends clomiphene citrate as the primary treatment for ovulation induction in women with PCOS, with gonadotropins used if clomiphene treatment fails 1.
- Metformin may improve ovulation frequency, but its effects on early pregnancy are not well established, and there is no evidence-based need to continue metformin once pregnancy is confirmed 1.
- Randomized controlled trials have not demonstrated a benefit of metformin in preventing spontaneous abortion or gestational diabetes in women with PCOS 1.
- Metformin crosses the placenta and may have effects on fetal growth and development, with some studies suggesting an increased risk of prematurity and higher BMI in childhood 1.
Clinical Considerations
- Metformin may be considered for women with PCOS who have insulin resistance and hyperandrogenism, but its use should be individualized and carefully monitored 1.
- The typical dosage of metformin is 500-1000mg twice daily, with a minimum treatment duration of 3-6 months to assess efficacy.
- However, due to the limited evidence and potential risks, metformin should not be used as a first-line treatment for infertility in women with PCOS, and other treatments such as clomiphene citrate and gonadotropins should be considered first 1.
From the FDA Drug Label
Females of Repropective Age: Inform females that treatment with metformin hydrochloride tablets may result in ovulation in some premenopunkal anovulatory women which may lead to unintended pregnancy [see Use in Specific Populations ( 8.3) ].
The FDA drug label does not explicitly recommend metformin for infertility treatment, but it does mention that it may result in ovulation in some premenopausal anovulatory women, which could potentially aid in fertility. However, this is not a direct recommendation for using metformin to treat infertility. Therefore, a conservative clinical decision would be to not use metformin solely for the purpose of treating infertility without further evidence or guidance from a healthcare provider. 2
From the Research
Metformin for Infertility
- Metformin may improve live birth rates in women with polycystic ovary syndrome (PCOS) compared to placebo 3, 4
- The addition of metformin to clomiphene citrate (CC) may increase clinical pregnancy rates, but the evidence is uncertain for live birth rates 3, 4
- Metformin may reduce the incidence of ovarian hyperstimulation syndrome (OHSS) in women with PCOS undergoing IVF or ICSI treatment 5, 6
- The use of metformin in non-obese women with PCOS may be associated with a slight increase in clinical pregnancy rate, but the evidence is limited 7
Comparison with Other Treatments
- Letrozole may be more effective than metformin in improving live birth and clinical pregnancy rates in women with PCOS 3
- Metformin may be comparable to CC in terms of clinical pregnancy rate, but the evidence is uncertain for live birth rates 3, 4
- The combination of metformin and CC may be more effective than metformin alone in improving clinical pregnancy rates, but the evidence is limited 7