No science just yet... [ x ]

No science just yet... [ x ]

However, studies since 2004 now show that mammals may continue to produce new eggs throughout their lives, rather than being born with a finite number as previously thought. Researchers at the Massachusetts General Hospital in Boston, US, say that if eggs are newly created each month in humans as well, all current theories about the aging of the female reproductive system will have to be overhauled. [ x ]

No science just yet... [ x ]

Follicle Stimulating Hormone (FSH) is released by the pituitary gland which is carried to the ovaries to stimulate the follicles. As FSH levels rise, some of the eggs respond with low levels of oestrodiol. By doing so the ovaries communicate back to the pituitary gland that the egg follicles have been stimulated and FSH production slows down.

However, when the supply of egg follicles is low and they are unresponsive to stimulation, the pituitary gland tries to compensate by producing more FSH every month. The overall levels of FSH rise. [ x ]

No science just yet... [ x ]

A study published in the Middle East Fertility Society Journal compared results of GnRH agonist long protocol vs. short protocol in women forty years or older undergoing ICS cycles.  The study was a multicenter comparative trial that included a total of 531 women ranging between 40-47 years old.  285 women received the long protocol while 246 women received the short protocol. All women had FSH less than 20 before the start of treatment.  Women with previous poor response were excluded from the study.

In total, among 531 participants, clinical pregnancy was achieved in 101 women (19%) and the miscarriage rate was 32% - mainly in the first eight weeks. There was a wide variation between the two protocols with the long protocol achieving a pregnancy rate of 26.6 % while the short protocol achieved only a 10.2% pregnancy rate. No cases of severe OHSS were reported. The cost of drugs were significantly reduced with the short protocol.

The study concluded that the long protocol of GnRH agonist was better than short protocol in women with age of forty or above. [ x ]

Women are born with about 2 million eggs in their ovaries, and they don’t make any new eggs during their lifetime.  Prior to puberty, about eleven thousand eggs die every month so that by her teens, a woman has only 300,000 - 400,000 remaining eggs.  From her teens onwards, approximately one thousand eggs are destined to die each month.

This phenomenon is completely independent of any hormone production, birth control pills, pregnancies, nutritional supplements, or even health or lifestyle. Nothing stops this inexorable death of approximately one thousand eggs every month regardless of ovulation, ovarian inhibition, or stimulation. Whenever the woman runs out of her supply of eggs, the ovaries cease to make estrogen, and she goes through menopause.

By age 37, the average woman will be down to only about 25,000 remaining eggs.  At this stage, menopause will occur in approximately 13 years.  Thus, the average woman begins to become infertile by the age of 37 or earlier, entering the menopause by the age of 50. [ x ]

No science just yet... [ x ]

No science just yet... [ x ]

No science just yet... [ x ]

Each egg in a woman's ovaries is enclosed within a resting follicle.  Every day, 30-35 of these resting follicles begin their 85 days of development toward eventually trying to ovulate.  At any time, a view into an ovary reveals follicles (with their enclosed eggs) in every stage of resting or growing.  Follicles can be :

• Early primordial, or resting, follicles
• Larger primary follicles
• Larger pre-antral follicles (which are beginning to form a fluid-filled space)
• Antral follicles

It is the antral follicles which can be seen under ultrasound at a size of approximately 1-2mm in diameter.  In addition, at midcycle, on day 14, there is normally a dominant pre-ovulatory follicle.

Upon reaching the antral stage, the follicles finally become sensitive to the hormones of the monthly menstrual cycle, causing them to rapidly die and disappear if they are not rescued by FSH.  Every month, only one, out of the one thousand that tried, will be ovulated ready for fertilization. [ x ]

The number of follicles per day that begin to become antral, and thereby capable of rescue from death by FSH stimulation, is inversely related to the age of the woman. The younger the woman and the larger the total number of eggs in her ovaries, the greater the number of eggs in any given month, or any given day, that will leave the resting phase and develop into antral follicles (of which only one per month is destined to ovulate; all the others will die). [ x ]

During the first 70 days of a follicle’s development, it is completely independent of any hormonal influence.  FSH and the monthly hormonal cycle have no influence until the follicle reaches somewhere between 0.2mm and 2mm in size.  At this point, these antral follicles begin to become sensitive to stimulation by FSH from the pituitary gland.  Prior to the time when these tiny follicles finally become ready to enter the current menstrual / ovulatory cycle, they are completely unaffected by whatever hormonal events have been taking place in the previous cycles. [ x ]

No science just yet... [ x ]

At the time of menstruation, as a result of the rapid fall in estradiol (estrogen) and progesterone secretion from the ovulated follicle of the previous month, the uterus sheds the lining that had built up during that month in preparation for pregnancy.  This sudden drop in estrogen causes the FSH secreted from the pituitary gland to rise dramatically around day 26 of the previous 28 day cycle. So, two days later, on day one of menstruation, this elevated FSH stimulates only the development of follicles that had left the resting pool 70 days earlier, and that are now antral.  As these antral follicles grow in response to FSH, they secrete estrogen and inhibin B, which in turn suppress further the pituitary secretion of FSH. Thus, by day 6, as the antral follicles become more mature, the FSH begins to decline. If these antral follicles were not rescued by the increased FSH level on day one of the menstrual cycle, when they have finally reached the antral size, they would die immediately.

A competitive struggle then ensues between the antral follicles to see which one will become the “lead follicle” that will ovulate on day 14.  The antral follicle that is most sensitive to FSH in the first few days of the cycle becomes even more sensitized to FSH, and thus gains the lead over all the other follicles (which die off because of lower and lower levels of FSH).  Once the dominant follicle gains the lead, it will never relinquish it, because it requires less FSH than the others to get the same degree of stimulation.

Because FSH continually declines toward the middle of the cycle just prior to ovulation, all the other antral follicles that month (which have finally become hormone dependent after almost three months of non-hormone-related growth) will die.  When they reach this stage of development, the follicles are completely dependent on FSH for survival. Once the estrogen production exponentially peaks, around day 12 or 13, it stimulates a dramatic rise in LH from the pituitary gland, and that rise in LH is what prepares the one remaining follicle for ovulation.

IVF uses FSH injections in the early part of the cycle so that the FSH level never declines, as it would normally.  This sustained elevation of FSH, sustains almost all of the antral follicles so that no single follicle can gain dominance over the others.  Therefore, the number of eggs retrieved in a hormonal stimulation cycle for IVF is directly reflective of a woman's antral follicle count, and her antral follicle count is directly reflective of the total remaining number of eggs. [ x ]