Usually, in healthy women, the ratio between LH and FSH usually lies between 1 and 2. In polycystic ovary disease women, this ratio becomes reversed, and it might reach as high as 2 or 3 (8). As a result of raised LH/FSH ratio, ovulation does not occur in polycystic ovary disease patients (9).
FSH and LH are often both in the range of about 4-8 in young fertile women. In women with polycystic ovaries the LH to FSH ratio is often higher – for example 2:1, or even 3:1. With PCOS we often see the FSH in the range of about 4-8 as well – but often the LH levels are 10-20.
In males, FSH stimulates the Sertoli cells resulting in spermatogenesis and LH causes the interstitial Leydig cells of the testes to produce testosterone. The reference range for FSH and LH in adult females is: The reference range for FSH in adult males is 2 – 12 IU/L and for LH is 2 – 9 IU/L.
What If Luteinizing Hormone Levels Are Out of Balance? A low LH level suggests that your pituitary gland might be malfunctioning, preventing the LH surge that's involved with menstruation. Higher-than-normal LH levels – when seen with high FSH levels – can be a sign of ovarian failure (which can result in infertility.
However, in normal LH/FSH group, serum level of AMH was only positively correlated with BMI (r = 0.428). Conclusion: The PCOS patients with higher LH/FSH ratio are primarily caused by hypothalamic-pituitary dysfunction, while the PCOS patients with normal LH/FSH ratio are mainly caused by metabolic disorders.
Women with PCOS usually have low to normal levels of FSH, but high levels of LH. Because LH is already high, there is no LH surge that occurs.
Gonadotropin levels greater than 30 mIU/ml are typically diagnostic of menopause, with the ratio of FSH to luteinizing hormone (LH) being greater than 1. After oophorectomy in a woman of reproductive age, there is a variable rise in gonadotropins.
Time to Test: Day 3 - Normal Range: <7 mIU/ml
o A normal LH level is similar to FSH. o An LH that is higher than FSH is one indication of PCOS.
Malfunction of the pituitary gland
The pituitary gland produces and secretes FSH and LH. The ovaries cannot ovulate properly if too much or too little of these hormones is produced. The pituitary gland may not function properly due to physical injury, a tumor or a chemical imbalance in the pituitary gland.
LH levels during ovulation
Your LH levels will be at their highest just after your LH surge around ovulation (mid-cycle). If you have your LH levels tested around this time, you could expect them to sit within the range of 12.2 to 118.0 IU/L. Again, anywhere within this range would be considered normal by your doctor.
Normal Results
Before menopause: 5 to 25 IU/L. Level peaks even higher around the middle of the menstrual cycle. Level then becomes higher after menopause: 14.2 to 52.3 IU/L.
Luteinizing hormone (LH) plays a key role in gonadal function. LH in synergy with follicle stimulating hormone (FSH) stimulates follicular growth and ovulation. Thus, normal follicular growth is the result of complementary action of FSH and LH.
Ovulation: A surge in LH causes your ovary to release a mature egg around the second week of each menstrual cycle. A high LH level around this time means that you're at that moment in your cycle when you're most likely to get pregnant.
Menopause Markers
Gonadotropin secretion increases dramatically after menopause. Follicle-stimulating hormone (FSH) levels are higher than luteinizing hormone (LH) levels, and both rise to even higher values than those seen in the surge during the menstrual cycle. The FSH rise precedes the LH rise.
Levels of LH are low for most of the monthly menstrual cycle. However, around the middle of the cycle, when the developing egg reaches a certain size, LH levels surge to become very high. A woman is most fertile around this time. People refer to this interval as the fertile window or fertile period.
Sometimes, elevated follicle-stimulating hormone (FSH) levels are measured to confirm menopause. When a woman's FSH blood level is consistently elevated to 30 mIU/mL or higher, and she has not had a menstrual period for a year, it is generally accepted that she has reached menopause.
FSH causes ovarian follicles to enlarge and produce estrogen. Over time, fewer and fewer follicles remain to be stimulated and thus estrogen levels decline as a woman ages. This decline in estrogen leads to an increase in FSH as there is not enough estrogen being produced to "turn off" the brain's production of FSH.
Why measure around Day 2? At this time, E2 is at its lowest so FSH should be at its highest. If the E2 level on Day 2 is > 200pmol/l, then follicle growth will have already started, and the measurement of the FSH is not reliable because the raised E2. will have already started to suppress the FSH level.
If you are woman, high LH levels may mean you: Are not ovulating. If you are of childbearing age, this may mean you have a problem in your ovaries. If you are older, it may mean you have started menopause or are in perimenopause.
If you have a persistent change of seven days or more in the length of your menstrual cycle, you may be in early perimenopause. If you have a space of 60 days or more between periods, you're likely in late perimenopause. Hot flashes and sleep problems. Hot flashes are common during perimenopause.
The first sign of the menopause is usually a change in the normal pattern of your periods. You may start having either unusually light or heavy periods. The frequency of your periods may also be affected. You may have one every two or three weeks, or you may not have one for months at a time.