From the Research
An elevated LH to FSH ratio is a significant diagnostic marker for Polycystic Ovary Syndrome (PCOS), typically considered when LH is two to three times higher than FSH, as supported by the most recent study 1. This hormonal imbalance contributes directly to the reproductive and metabolic dysfunction seen in PCOS. The elevated LH stimulates excessive androgen production by the ovarian theca cells, leading to symptoms like hirsutism, acne, and male-pattern baldness. Meanwhile, the relatively lower FSH levels impair follicular development, resulting in chronic anovulation and the formation of multiple small follicles that give PCOS its name. Some key points to consider:
- The LH:FSH ratio is particularly valuable when measured during the early follicular phase (days 3-5) of the menstrual cycle, though it's essential to note that not all women with PCOS will show this elevated ratio.
- The imbalance also contributes to insulin resistance commonly seen in PCOS, creating a cycle where hyperinsulinemia further increases androgen production.
- Understanding this ratio helps clinicians determine appropriate treatment approaches, which may include hormonal contraceptives to regulate cycles, anti-androgens to address excess hair growth, or insulin-sensitizing medications like metformin, as indicated by studies such as 2, 3, 4, and 5.
- A study from 2023 1 found that an elevated baseline LH/FSH ratio is associated with poor ovulatory response but better clinical pregnancy and live birth in Chinese women with PCOS after ovulation induction, highlighting the complexity of LH/FSH ratio in predicting outcomes in PCOS patients.
- It is crucial to consider the most recent and highest quality evidence when making clinical decisions, and in this case, the 2023 study 1 provides valuable insights into the significance of the LH/FSH ratio in PCOS.