From the Guidelines
Both the Mirena coil and low-dose estrogen therapy can potentially contribute to weight gain in patients with polycystic ovary syndrome (PCOS), though individual responses vary significantly. The Mirena coil contains progestin (levonorgestrel), which may cause fluid retention and increased appetite in some users, potentially leading to weight gain of 2-5 pounds 1. Low-dose estrogen can also cause fluid retention and may affect fat distribution in some patients. For PCOS patients who already have hormonal imbalances that predispose them to weight gain, these hormonal treatments might exacerbate this tendency.
Some key points to consider:
- Weight gain over 10 years among women with PCOS is significantly greater than in unaffected women in a longitudinal community-based study 1.
- Central obesity increases over time with a progressive increase in WHR between 20–25 years and 40–45 years 1.
- Lifestyle interventions that reduced weight by as little as 5% of total body weight have been shown to have metabolic, reproductive and psychological benefits in PCOS patients 1.
- Behavioural and cognitive behavioural intervention approaches can target behaviours, their antecedents and consequences and cognitions that maintain positive energy balance and promote weight gain, and are common in weight management 1.
However, it's essential to note that many PCOS patients use these treatments without significant weight changes, and the benefits for managing PCOS symptoms often outweigh this potential side effect. If weight gain occurs, lifestyle modifications including regular exercise and a balanced diet can help manage it. Patients should monitor their weight over the first 3-6 months of treatment and discuss persistent concerns with their healthcare provider, who may suggest alternative treatments if weight gain becomes problematic 1.
From the Research
Mirena Coil and Low Dose Estrogen Effects on PCOS Patients
- The Mirena coil, also known as the levonorgestrel-releasing intrauterine system (LNG-IUS), is a progestogen-only contraceptive that has been studied in women with polycystic ovary syndrome (PCOS) 2.
- Research has shown that the LNG-IUS can have beneficial effects on PCOS symptoms, such as reducing ovarian volume and improving menstrual regularity 2.
- However, the study also found that the LNG-IUS was associated with a 2.3% increase in abdominal circumference and a 3.4% increase in fasting glycemia in PCOS patients after 6 months of use 2.
- Another study found that a low-dose estrogen-antiandrogen combination (Diane-35) was effective in reducing hormonal disturbances and improving symptoms of androgenization in PCOS patients, but some patients reported side effects such as weight gain 3.
Weight Gain and PCOS
- Weight gain is a common concern for PCOS patients, and hormonal contraceptives can have varying effects on weight 4, 3.
- The study on the LNG-IUS found that it was associated with a small increase in abdominal circumference, but not with significant weight gain 2.
- Another study found that some patients reported weight gain as a side effect of a low-dose estrogen-antiandrogen combination (Diane-35) 3.
- However, the evidence suggests that the Mirena coil and low-dose estrogen may not be directly associated with significant weight gain in PCOS patients, but individual results may vary 4, 3, 2.