Science and Technology
About Infertility
General Fertility and Infertility Information | Assisted Reproductive Technologies and IVF | Fertility Terms
General Fertility and Infertility Information
Alexander Tsiaras: Conception to birth — visualized
What is Infertility?
Infertility is defined as the inability to achieve pregnancy after 12 consecutive months (6 months if 35 or over) of trying to conceive through regular unprotected intercourse. It should not be confused with sterility, which is defined as being physically incapable of pregnancy. 7.3 million Americans, about 12% of all American couples, are infertile.
What is secondary infertility?
Secondary infertility is the inability to get pregnant after having at least one successful birth.
Is either partner more likely to be the cause of infertility?
1/3 of infertility is male related, 1/3 third is female related and 1/3 of infertility is a combination of male and female or unexplained.
How does age affect fertility?
Fertility decreases with age due to poor egg quality and reduced bioenergetics. By age 30 a healthy woman has around a 20% chance of conceiving per month or a 75% of conceiving naturally within 1 year. By age 40 a woman has a 5% chance of achieving pregnancy naturally or a 44% chance of conceiving within 1 year. We have links to many research articles on the science behind aging and fertility in our Resources Section.
What causes infertility in women?
There are several causes of infertility. They include endometriosis, ovulation disorders, fallopian tube damage or blockage, cervical mucus problems, age, PCOS, damage caused by cancer and cancer treatments, and early menopause. These terms are explained in the Fertility Terms Section.
What causes male infertility?
Male infertility is often due to low sperm counts, the motility (ability to move) of the sperm, the sperm’s capability to fertilize, or a combination of factors. Sperm motility is frequently the result of an abnormality of the testicles, a varicocele, or inflammation within the testes. The sperm count can be influenced by several factors as well. These include overheating the testes through too tight underwear, diet, use of caffeine, alcohol, and tobacco, hormonal disorder, and radiation.
Does a woman run out of eggs?
It had been widely accepted that a woman was born with a limited number of eggs. It was thought that a female begins life with around 1,000,000 eggs. Of these, only 300,000 were thought to remain by puberty and 300 to 400 to ever be ovulated. But, in 2012 this dogma was challenged in a paper that found proliferative germ cells that sustain oocyte and follicle production in the postnatal mammalian ovary. This means that women do not have a limited number of eggs.
What is endometriosis?
Endometriosis is a female reproductive disorder in which the endometrial tissue (lining of the uterus) grows outside of the uterus. It can cause infertility by blocking tubes with tissue or through scarring. More information can be found here: http://www.resolve.org/diagnosis-management/infertility-diagnosis/endometriosis.html.
What is PCOS?
Polycystic ovary syndrome (PCOS) is associated with several different conditions including infertility, obesity and type 2 diabetes. The postulated causes of PCOS are somewhat controversial and include over-secretion of pituitary luteinizing hormone (LH), overproduction of ovarian androgens and insulin resistance. In some cases it has been shown that treating type 2 diabetes with an insulin sensitizer has been able to improve not only the symptoms of diabetes but also fertility. But, with various postulated causes for PCOS and differences in individuals’ responses to insulin sensitizers, it may be that PCOS is a syndrome that needs to be diagnosed and treated on an individual basis.
How long do sperm live after ejaculation?
Sperm can live between 3–5 days with a female’s body. Thus, fertilization can happen days after sex occurs.
How long do eggs live after ovulation?
Eggs live up to 24 hours after ovulation.
Assisted Reproductive Technologies and IVF
What is in vitro fertilization (IVF)?
IVF is an Assisted Reproductive Technology (ART) procedure in which a female’s egg cell is removed from the body and fertilized by sperm outside of the body (in vitro). Fertilization can be done by placing the egg cell and sperm in a fluid medium until a sperm penetrates the egg or through ICSI. After fertilization the developing embryo is physically deposited within the uterus. The first successful IVF procedure was performed in 1978 with the birth of Louise Brown and it was not brought to the United States until 1981. Since then there have been over 500,000 IVF births in the United States and 4 million IVF births worldwide.
What is ICSI (Intra Cytoplasmic Sperm Injection)?
ICSI is a procedure in which the male’s sperm is injected into a female’s egg using a small needle to achieve fertilization.
Fertility Terms
Assisted Reproductive Technology (ART)
The Center for Disease Control (CDC) defines ART as any procedure in which eggs or sperm are handled.
Blastocyst
After fertilization of the egg, the embryo’s cells begin to divide. The single cell divides from one cell to two to four to eight and onward. Five to seven days after fertilization, the embryo has developed a central cavity that is filled with fluid. The cells that surround the cavity will become the placenta and the inner cells will become the fetus.
Cervical Mucus
Cervical mucus is the mucus and liquid secreted by the cervix. Its volume and viscosity are controlled by estrogen. Cervical mucus’s role is to protect the sperm from the acidity of the vagina and to aid the sperm in their travel to the fallopian tubes and the egg.
Endometriosis
Endometriosis is a female reproductive disorder in which the endometrial tissue (lining of the uterus) grows outside of the uterus. It can cause infertility by blocking tubes with tissue or through scarring. More information can be found here: http://www.resolve.org/diagnosis-management/infertility-diagnosis/endometriosis.html
Female reproductive organs
Infertility
Infertility is defined as the inability to achieve pregnancy after 12 consecutive months (6 months if 35 or over) of trying to conceive through regular unprotected sex. It should not be confused with sterility, which is defined as being physically incapable of pregnancy. 7.3 million Americans, about 12% of all American couples are infertile.
Intra Uterine Insemination (IUI)
IUI is an ART in which washed sperm are placed within the female’s uterus.
In Vitro Fertilization (IVF)
IVF is an Assisted Reproductive Technology (ART) procedure in which a female’s egg cell is removed from the body and fertilized by sperm outside of the body (in vitro). Fertilization can be done by placing the egg cell and sperm in a fluid medium until a sperm penetrates the egg or through ICSI. After fertilization the developing embryo is physically deposited within the uterus. The first successful IVF procedure was performed in 1978 with the birth of Louise Brown and it was not brought to the United States until 1981. Since then there have been over 500,000 IVF births in the United States and 4 million IVF births worldwide.
Male reproductive organs
Motility
Motility is the ability of the sperm to move.
Oocyte
An oocyte is a female germ cell. It is also known as an egg cell.
PCOS
Polycystic ovary syndrome (PCOS) is associated with several different conditions including infertility, obesity and type 2 diabetes. The postulated causes of PCOS are somewhat controversial and include over-secretion of pituitary luteinizing hormone (LH), overproduction of ovarian androgens and insulin resistance. In some cases it has been shown that treating type 2 diabetes with an insulin sensitizer has been able to improve not only the symptoms of diabetes but also fertility. But, with various postulated causes for PCOS and differences in individuals’ responses to insulin sensitizers, it may be that PCOS is a syndrome that needs to be diagnosed and treated on an individual basis.
Premature Ovarian Failure
Premature ovarian failure is the cessation of normal function of a female’s ovaries before the age of 40.
Secondary Infertility
Secondary infertility is the inability to get pregnant after having at least one successful birth.
Tubal Factor Infertility
Tubal factor infertility is caused by the blockage of the fallopian tubes. This blockage does not allow the sperm and the egg to unite and for fertilization to occur.
Unexplained Infertility
When all standard causes of infertility have been ruled out and ovulation and sperm tests are normal, a couple’s infertility is called unexplained infertility. 10 to 15% of all infertile couples are diagnosed with unexplained infertility.
Varicocele
A varicocele is an abnormally enlarged vein in a male’s scrotum that prevents blood from draining from the testicles. It can hamper the production sperm and lead to male infertility.
Washed Sperm
Washed sperm are sperm that have been separated from seminal fluid (ejaculate).
Zygote
The zygote is the first stage of development for an embryo. It is the single cell that is created when the two gametes (one from the female and one from the male) unite.