From the Guidelines
Side Effects of Metformin on Frozen Embryo Transfer
Metformin is not recommended for use in frozen embryo transfer due to potential risks to the offspring, including higher BMI and increased obesity 1.
- The patient's current treatment with Lupron (leuprolide) 3.75mg and letrozole 5mg for endometriosis is not directly related to the use of metformin.
- The patient's weight gain and impaired glucose regulation (Hemoglobin A1c 5.8) may be managed with alternative treatments that do not involve metformin, considering the potential long-term risks to the offspring.
- Metformin readily crosses the placenta, resulting in umbilical cord blood levels of metformin as high or higher than simultaneous maternal levels 1.
- A meta-analysis demonstrated that metformin exposure resulted in smaller neonates with an acceleration of postnatal growth, resulting in higher BMI in childhood 1.
- The patient's history of endometriosis is not a contraindication for metformin use, but the potential risks to the offspring should be carefully considered.
- Alternative treatments for impaired glucose regulation should be explored, considering the patient's plans for frozen embryo transfer and the potential long-term risks associated with metformin use.
From the FDA Drug Label
What are the side effects of metformin hydrochloride tablets? Lactic acidosis Metformin, the active ingredient in metformin hydrochloride tablets, can cause a rare but serious condition called lactic acidosis (a buildup of an acid in the blood) that can cause death. Common side effects of metformin hydrochloride tablets include diarrhea, nausea, and upset stomach About 3 out of every 100 people who take metformin hydrochloride tablets have an unpleasant metallic taste when they start taking the medicine. Metformin hydrochloride tablets rarely cause hypoglycemia (low blood sugar) by themselves.
The side effects of metformin on frozen embryo transfer in a 31-year-old female with a history of endometriosis, currently being treated with Lupron (leuprolide) 3.75mg and letrozole 5mg, presenting with weight gain and impaired glucose regulation (Hemoglobin A1c 5.8) may include:
- Lactic acidosis: a rare but serious condition that can cause death
- Gastrointestinal symptoms: diarrhea, nausea, and upset stomach
- Unpleasant metallic taste: experienced by about 3 out of every 100 people
- Hypoglycemia: rarely caused by metformin hydrochloride tablets by themselves, but can happen if the patient does not eat enough, drinks alcohol, or takes other medicines to lower blood sugar 2
From the Research
Side Effects of Metformin on Frozen Embryo Transfer
- There is no direct evidence on the side effects of metformin on frozen embryo transfer in a 31-year-old female with a history of endometriosis, currently being treated with Lupron (leuprolide) 3.75mg and letrozole 5mg, presenting with weight gain and impaired glucose regulation (Hemoglobin A1c 5.8) 3, 4, 5, 6, 7.
Metformin and Endometriosis
- Metformin has been shown to alleviate endometriosis and potentiate endometrial receptivity via decreasing VEGF and MMP9 and increasing leukemia inhibitor factor and HOXA10 3.
- Metformin may modify the stroma-epithelium communication via Wnt2/β-catenin, and has anti-inflammatory and anti-proliferative effects in the treatment of endometriosis 4.
Frozen Embryo Transfer
- The freeze-all strategy has emerged as an alternative to fresh embryo transfer during in vitro fertilization cycles, with potential advantages including improved pregnancy rates and reduced risk of ovarian hyperstimulation syndrome (OHSS) 5.
- Letrozole has been shown to be a good choice for endometrial preparation in women with normal menstrual cycles, with higher pregnancy rates and lower side effects compared to hormone replacement therapy 6.
Effects of Metformin, Letrozole, and Atorvastatin on Endometriosis
- Metformin, letrozole, and atorvastatin have been shown to induce apoptosis and have anti-inflammatory effects on ovarian and peritoneal endometriosis in experimental models 7.