A 28 yrs old lady, is suspected to have polycystic ovarian disease ,sample for testing LH and FSH are best taken on the following days of menstrual cycle
**Core Concept**
Polycystic ovary syndrome (PCOS) is a complex endocrine disorder characterized by ovulatory dysfunction, hyperandrogenism, and polycystic ovaries. The diagnosis of PCOS is primarily based on clinical and biochemical findings, including hormonal imbalances. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are key hormones involved in the reproductive cycle, and their levels can provide valuable information in diagnosing PCOS.
**Why the Correct Answer is Right**
In PCOS, there is often an imbalance in the LH/FSH ratio, with elevated LH levels and normal or low FSH levels. The LH surge is typically observed on the day of ovulation, around day 14 of a 28-day menstrual cycle. Therefore, blood samples for LH and FSH testing are best taken on the third day of a regular menstrual cycle (day 3) to assess baseline hormone levels, and on the day of ovulation (day 14) to evaluate the LH surge. This allows for an accurate assessment of the LH/FSH ratio and helps in confirming the diagnosis of PCOS.
**Why Each Wrong Option is Incorrect**
**Option A:** This option may seem plausible, but it is not the best time for testing LH and FSH levels. Day 1 is typically the first day of menstruation, and hormone levels may not have returned to baseline yet.
**Option B:** Day 21 is too late in the menstrual cycle to assess the LH/FSH ratio accurately, as it is closer to the time of ovulation.
**Option C:** This option is incorrect because it does not take into account the variability in menstrual cycles and the timing of ovulation.
**Clinical Pearl / High-Yield Fact**
In PCOS, the LH/FSH ratio is often elevated, with a ratio of 2:1 or higher. This is a key diagnostic criterion for PCOS and can help differentiate it from other causes of hyperandrogenism.
**Correct Answer:** D. Day 3 and day 14 of a regular menstrual cycle.