How are sperm and eggs produced?
In both men and women, there are stages of conception which, if completed appropriately, lead to fertility and conception. These stages are distinct and precise, so if there are any anomalies, missed steps or interruptions, infertility can occur.
In men, the stages of conception include:
- Sperm is produced in the seminiferous tubules, which are lined with approximately 13 rows of baby sperm cells, in different stages of development. These baby sperm cells are called "stem" cells.
- These stem cells being to divide to create "daughter" cells which will eventually mature into spermatocytes (sperm-at-oh-sites) or something like "toddler" sperm. This is in response to testosterone.
- The "toddler sperm" will continue to mature to become spermatids (sperm-ah-tids) or "teenage" sperm.
- The "teenage sperm" continue to mature to become adult sperm or spermatozoa (sperm-at-oh-zoh-uh), though they are not very mobile at this time.
- The adult sperm are carried to the epididymis - tubes where they will develop defined heads and tails, and where they will be stored until needed. They can hold approximately 440 million sperm.
- There are 6 distinct parts to that maturation of sperm, which take a total of 74 days to complete.
In women, there are also specific stages in conception:
- Women are born with all of the eggs or ova that they will ever have, these eggs are stored in the ovaries, in an immature state, and number approximately 400, 000 at time of puberty.
- In response to a hormone called "follicle-stimulating hormone" or FHS, the ovary begins to mature about 20 ova, inside small follicles in the ovary. This process stimulates the production of estrogen.
- As the estrogen level rises, it signals the uterus to begin reproducing the cells in its lining, in preparation for receiving an ova.
- A third hormone, called luteinizing (loo-tin-eye-zing) hormone or LH, then encourages the ripening of the follicle, and stimulates it to rupture, to release the mature ova.
- The mature ova travels into the fallopian (fuh-lo-pee-an) tube, where it hopes to become fertilized. Fertilization must occur within 72 hours of release, or the ova will die.
- If fertilized, when it reaches the uterus, it will attach to the wall of the uterus and being to divide, creating a fetus. If it is not fertilized, it will reach the wall, the wall will recognize the hormonal signature of non-fertilization, and the lining of the uterus will shed, causing a "period."
As you can see, the stages of conception involve many complex steps that, if one step is altered, can result in infertility. Your Infertility Specialist can evaluate you to determine if there are errors or alterations in your stages of conception which are preventing pregnancy.
Infertility Frequently Asked Questions
Why would someone want to get a vasectomy?
Why did my wife get pregnant after my vasectomy?
What are the risks of getting a vasectomy?
What are the risks of reversing a vasectomy?
Are there any alternatives to vasectomy?
How much does a vasectomy and a reversal cost?
What should I know about reversing my vasectomy?
What is a vasectomy and how is it done?
Why do I feel like I am grieving over my infertility?
What does ovulation have to do with infertility?
What causes a "period?"
What is BBT and how will it help my infertility?
What is endometriosis?
Does the position of my uterus affect my ability to get pregnant?
How does my thyroid dysfunction relate to infertility?
What are the hormones involved with fertility and what do they do?
How does stress impact fertility?
What are the main causes of female infertility?
What causes male infertiliy
What is impotence and what causes it?
What kinds of structural problems can cause male infertility?
What role do hormones play in male fertility?
What role does sperm motility problems have in male infertility?
What kinds of testicular problems can contribute to infertility?
What causes problems with sperm transport?
What is hemachromatosis?
Why would stress contribute to infertility?
How is male infertility treated?
What is the definition of infertility?
What causes infertility?
Why do people questions couples who don't have children?
Why do I feel inadequate because I have fertility problems?
How are sperm and eggs produced?
How does the structure of my reproductive organs impact fertility?
What are some external causes of infertility?
How do hormones impact infertility?
What is involved with surrogacy?
What is In Vitro Fertilization and what is involved with the process?
What are "fertility drugs" and what do they do?
How would one go about Egg Donation?
What is In Utero Fertilization and how is it done?
What are some alternative therapies for treating infertility?
What can be done to treat infertility caused by structural problems?
Are there surgical options available to treat my infertility?
What exactly is a fertility clinic?
What things should I consider when thinking about infertility treatment?
What is involved in sperm donation?
What is a Reproductive Endocrinologist?
Why does someone choose tubal ligation?
What is post tubal ligation syndrome?
How is a tubal ligation performed?
What should I consider when thinking about a tubal reversal?
What alteratives do I have besides tubal ligation for long-term birth control?
What are the risks of having a tubal and a tubal reversal?
What are the risks related to tubal ligation reversal?
Why might someone get pregnant after a tubal ligation?
What is the origin of Artificial Insemination?
How is donor sperm used in artificial insemination?
When would a surrogate be used with artificial insemination?
What are the laws governing sperm and egg donation?
What are the risks in artificial insemination?
What are my chances of success using artificial insemination?
What is "artificial insemination?"
What is the process for becoming a sperm donor?
How do I go about getting IVF insurance?
Can I use personal loans to pay for IVF?
How much does IVF cost?
How can I finance IVF?
What are third party loans in terms of financing IVF?
Will my insurance cover IVF?
What is "shared risk" in terms of IVF?
Are public funds used for IVF financing?
What is the role of Medical Counseling in fertility treatment?
How can a Financial Counselor help with fertility treatment?
What kinds of infertility counseling are available?
How does Psychological Counseling help during fertility treatment?
How does one go about choosing an Infertility Center?
Where can I get information and about infertility?
How do I go about finding a Fertility Specialist?
Where can I get more information about infertility?
Can I become an egg donor?
What are the legal ramifications of egg donation?
What are the risks and potential complications of egg donation?
What role do fertility drugs play in egg donation?
What role does egg donation play in in vitro fertilization?
What is process for being a donated egg recipient?
What should I look for in an Egg Donation Center?
What is the process of egg donation?
What are the potential risks and complications of IVF?
What is in vitro fertilization?
What are the alternatives to using IVF?
What are the steps involved with in vitro fertilization?
When would IVF be used to treat infertility?
How much does in vitro fertilization cost?
What kinds of fertility drugs are used during IVF?
What are some of the moral and ethical dilemmas associated with IVF?