Ovulation is a critical point in the cycle, and I think an important aspect on which to focus. This is especially important with regard to concussion. Why? One reason is that ovulation produces progesterone. Progesterone is becoming increasingly recognized as helpful to concussion management and recovery.
Hormones
The pulse actions of the three pituitary hormones that initiate ovulation are significant. As you review materials and information, you’ll often see references to the GnRH, LH, and FSH pulse. Keep this in mind and commit it to memory. It’s key. If the surge doesn’t occur as it should, ovulation might not occur, resulting in disrupted hormone production and levels. This, in turn, may cause other problems.
Characteristics
Normal
- Estrogen and progesterone level are lower in the Follicular Phase (pre-ovulatory)
- GnRH pulse results in the LH and FSH pulse
- LH and FSH pulses result in egg release from ovary
- Estrogen levels rise just before ovulation
- Progesterone is produced via the corpus luteum
- Progesterone levels rise after ovulation, and then drop if there’s no egg implantation
- Cycle is more regular in duration
Dysfunctional
- GnRH, LH, and FSH pulse surges do not occur or have lower levels than normal
- Progesterone is not produced
- Estrogen levels are low
- Luteal phase might shorten due to Luteal Phase Defect (LPD) and potentially affect fertility; more bleeding may occur
- Androgen levels (male hormones) might increase and result in Polycystic Ovary Syndrome (PCOS), which may also affect fertility
- Primary and secondary amenorrhea may occur and result in a lack of ovulation (and therefore progesterone levels, among other issues)
Life Phases
Here’s a quick overview of some aspects of ovulation pertinent to specific life phases.
Puberty
Typically, a girl’s first menstrual cycles are irregular. For the first year or so after menarche, they can also be anovulatory. A later menarche may result in a longer time frame in which regular ovulation is established. [1]
For the first year or so following menarche, periods may be anovulatory.
Childbearing Years
Obviously, pregnancy depends on ovulation.
Perimenopause
There is much variability during this time, which can last ten years or so. A lack of ovulation results in longer menstrual cycles and infrequent periods (the normal perimenopause process).
Menopause
When ovulation ceases, menopause occurs. The time after that one event is referred to as postmenopause.
Causes of Ovulation Problems
- Amenorrhea: hormone levels remain too low to initiate the pulse
- Female Athlete Triad: lack of adequate caloric intake results in amenorrhea, which can resuls in anovulatory cycles
- Pituitary issues
- PCOS: higher levels of LH and androgens (male hormones) such as testosterone; low levels of progesterone. Ovaries do not release eggs.
Related Posts
Menstrual Cycle Hormones at a Glance
[1] American Academy of Pediatrics “Menstruation in Girls and Adolescents: Using the Menstrual Cycle as a Vital Sign” Pediatrics 2006;118;2245
