Metformin Therapy for PCOS-Related Infertility
Introduction to Metformin Therapy
- The American College of Obstetricians and Gynecologists recommends that clomiphene citrate or letrozole, not metformin, should be the first-line ovulation induction agent for women with PCOS, as they are significantly more effective at achieving pregnancy and live birth compared to metformin alone 2
- Metformin should be initiated in patients with clinical markers of insulin resistance, metabolic syndrome features, or anovulation with metabolic dysfunction requiring metabolic optimization before or alongside ovulation induction 1, 2, 3
Metformin Dosing and Administration
- The target dose of metformin is 1,500-2,000 mg daily in divided doses, with a maximum dose of 2,550 mg daily 1, 2
- Metformin can be administered as 1,000 mg twice daily, 750 mg twice daily (using extended-release formulations), or 500 mg three times daily 1, 4
Critical Safety Concerns for Pregnancy Planning
- Metformin readily crosses the placenta and may be associated with higher BMI, waist circumference, and waist-to-height ratios in offspring, as well as increased obesity risk in childhood 2, 5
- The American College of Obstetricians and Gynecologists recommends that metformin should not be used in pregnant women with hypertension, preeclampsia, or those at risk for intrauterine growth restriction 2
Mandatory Monitoring Before and During Treatment
- Baseline requirements include renal function (eGFR), hepatic function, fasting glucose, and lipid profile 1, 3
- Ongoing monitoring includes renal function periodically, fasting glucose and lipid profile every 3-6 months, and pregnancy testing in sexually active women 1, 3
Expected Benefits Beyond Fertility
- Metformin provides metabolic improvements, including decreased LDL cholesterol and triglycerides, weight stabilization or modest loss, improved glucose tolerance over time, and reduced cardiovascular risk factors 1, 3