The Facts of Life: Examining Reproductive Health

Infertility

An erection is the result of increased blood flow to the penis. During sexual excitement, nerve impulses send about seven times the normal blood flow to two cylindrical structures - the corpora cavernosa - that run parallel with the urethra. The increased blood flow forces these sponge-like structures to swell and stiffen, producing an erection.

Three elements must cooperate to produce an erection. The first, sexual arousal, may be obtained through the senses of sight, touch, hearing and smell, and from thought and emotions. Second, the nervous system must communicate sexual excitation from the brain to the penis. And finally, blood vessels to the penis must relax to enable increased blood flow. When any one of these elements break down, impotence can result.

Impotence is recognized as a serious medical concern. In addition to the sensitive psychological and physical aspects for a man, impotence can also cause anxiety to sexual partners. Occasional impotence has no bearing on a man's masculinity, nor is it usually a commentary on his partner's desirability. Rather, situations at work, school, or in the home may raise anxiety levels which can result in temporary impotence.

There are several devices that can assist men who are impotent. Some may be surgically implanted in the penis to help maintain an erect state, or to create an erection at will. Other devices do not require surgery. For example, a pump which, when placed over the penis, creates a vacuum that forces blood into the penis to cause an erection. The erection is maintained by a small ring around the base of the penis. When the erection is no longer desired, the ring is simply removed and the penis returns to it flaccid state. There are also injections of medication given directly into the penis that cause erections.

Penile implant
The penile implant is one method of treatment for impotence, the inability to achieve erection of the penis. This implant uses a hydraulic system to reproduce the action of a functioning penis. The two tubes are implanted in the body of the penis. They are connected by tubing to a pump which is placed in the scrotum and then to a reservoir bulb which is placed in the abdomen. Squeezing the pump inflates the tubes and produces an erection. A valve on the pump can then reverse the process, allowing the penis to become normally flaccid.

Testicular implant
The testicular implant is employed for aesthetic reasons. It may be used when a testicle is removed due to cancer or trauma or in cases of an undescended testicle. The implant consists of a silicone rubber outer shell filled with a silicone gel.

Infertility And Assisted Reproduction
Each year millions of couples seek help for fertility problems. While most people assume that intercourse will lead to pregnancy, the chance of becoming pregnant is only approximately one in four. This is true for even the most fertile couples. A person's age, health, lifestyle and/or health habits may contribute to infertility. Infertility is usually defined as the inability of a couple to conceive after one year of unprotected intercourse.

The male reproductive system is responsible for approximately 50% of infertility. There must be enough active, healthy sperm for fertilization to occur. A sperm count below 20 million per ejaculate may indicate a fertility problem. Although there may be a sufficient number of sperm, to penetrate an egg, sperm must be of a certain shape and motility. Reduced fertilizing capacity may be due to abnormally shaped sperm or low sperm count in a man and mild endometriosis, cervical mucus deficiency, or cervical antibodies in a woman.

Assisted reproductive technologies (ART) attempt to improve the conditions for fertilization inside the body or actually facilitate the union of egg and sperm outside the body for eventual transfer to the uterus or fallopian tube. These technologies include intrauterine insemination (IUI), in vitro fertilization (IVF), gamete intrafallopian transfer (GIFT), pronuclear stage embryo transfer (PROST)/zygote intrafallopian transfer (ZIFT), subzonal sperm insertion (SZI), and intracytoplasmic sperm injection (ICSI). Intrauterine insemination does not always utilize ovarian hyperstimulation. There are many cases of IUI with a "natural cycle." These technologies require a woman to undergo hormonal treatment to stimulate egg production, and a minor surgical procedure to retrieve the eggs. Semen may be provided by the woman's partner or by an anonymous donor. It may have been previously frozen. It is always collected prior to the actual procedure.

Couples may use one or more of these methods, or may use a specific method more than once for successful fertilization to occur. While these treatments may increase the chance of pregnancy, none of them are guaranteed.

Embryo Cryopreservation
Embryos are prepared for freezing by first placing them stepwise into two specialized solutions which help protect the embryo from damage during freezing. They are then loaded into small, sterile straws. The straws are sealed, set into a rack, and placed inside a computerized freezer. The temperature of the freezer is lowered at a controlled rate according to a computer program. After the freezing process is completed, the straws are transferred to a storage tank filled with liquid nitrogen. This will be their home until they are removed at a later date for thawing.

After thawing, the embryos may be transferred to a healthy Fallopian tube using pronuclear stage embryo transfer (PROST)/zygote intrafallopian transfer (ZIFT) or transferred directly to the uterus, IVF-ET. Embryo freezing is available to couples who want children later in life, to surrogate mothers, and to couples in which one partner is terminally ill.

Gamete Intrafallopian Transfer (GIFT) Gamete intrafallopian transfer is a process in which the collected egg and sperm cells are placed together in a healthy fallopian tube by a surgical procedure called laparoscopy. This technology enables sperm cells to bypass some of the barriers they would face traveling to the egg under "natural" conditions. Unlike ZIFT/PROST, conception occurs within the woman's reproductive tract. Success depends upon normal sperm count and normal fertilization capacity. Couples may choose this method because of problems with mild endometriosis, unexplained infertility, low sperm production, or sperm antibodies. GIFT may sometimes be preferred over other assisted methods because fertilization takes place within the body (in vivo )rather than outside the body (in vitro).

45. Explanation of the GIFT process. Sperm and extracted eggs are placed into a fallopian tube

Intracytoplasmic Sperm Injection (ICSI)
Intracytoplasmic sperm injection is one of the most widely used methods of micromanipulation. Micromanipulation involves the use of small glass tools and fine controls to hold the egg and transport sperm.

In the laboratory, a sperm is directly injected into the egg cell. The embryologist uses a high-power magnification microscope to view the egg and sperm during this delicate procedure. ICSI enables sperm to bypass many obstacles to fertilization. All the eggs that have been retrieved from the woman will be manipulated in this manner. Once fertilization of the eggs is confirmed, the embryos are non-surgically deposited into the uterus. An average of 50% of the eggs inseminated in this manner will be fertilized. As with all forms of assisted reproductive technology, there is no guarantee of pregnancy.

Intrauterine Insemination (IUI)

46. Illustration of intrauterine insemination, sperm are inserted into the uterus

In this method, sperm (from either the partner or an anonymous donor) is injected into the uterus via a tiny catheter inserted through the cervix. In the presence of a low sperm count, mild endometriosis, unexplained infertility, cervical mucus deficiency, or cervical antibodies, intrauterine insemination may help to increase the chance of pregnancy. This procedure may be combined with hormone treatments to increase egg production.

Pronuclear Stage Embryo Transfer (PROST)/Zygote Intrafallopian Transfer (ZIFT)
PROST, also known as ZIFT, is identical to GIFT except that the extracted egg and sperm cells are first combined in a dish in the laboratory. Once fertilization is confirmed, the embryos, or fertilized eggs, are placed in a healthy fallopian tube by a surgical procedure called laparoscopy the day after egg retrieval. Here, development of the embryo occurs in the woman's reproductive tract. This method may be used when a man has a low sperm count and/or reduced fertilization capacity, or when a woman has unexplained infertility.

Semen Cryopreservation
Semen cryopreservation enables men who are anticipating a vasectomy, chemotherapy, radiotherapy, or toxic exposure to preserve their sperm. The procedure is offered because such treatments may lead to reduced fertility or sterilization. Frozen sperm may be used in various forms of assisted reproductive technologies.

After sperm is collected in a sterile container, a participant will sign a consent form to allow the freezing and storing of sperm. The seminal fluid is analyzed for sperm count, motility, ejaculate volume and consistency. A cryoprotectant (antifreeze) is added to the fluid to protect the sperm during the freezing process. The vials are then frozen in a temperature-controlled freezer and stored in a liquid nitrogen tank at -196 degrees Celsius (- 320.8 degrees Fahrenheit). Sperm may be kept indefinitely at this temperature.

Anonymous Sperm Donation
Anonymous sperm donations are used for artificial insemination in women whose partners are infertile or sterile, or where a male partner is lacking. The sperm is collected, cryopreserved, quarantined for six months, and stored in liquid nitrogen until needed. All donors and recipients remain anonymous. Signed documents protect donors from any future liability. Partners of artificially inseminated women are required to acknowledge paternity of any offspring. Offspring are not given any donor information other than medical history.

Sperm donors must meet strict criteria for various sperm quality parameters as well as health history and health status. Less than 10% of applicants are qualified to be donors. Certain steps are necessary to protect the recipients of the donor semen and ensure healthy offspring. Potential donors must complete a three generation medical history questionnaire, submit to a physical examination, and be tested for sexually transmissible diseases every six months.

The following automatically eliminates a participant from becoming a donor:

1. Sexual activity with a prostitute
2. Intravenous drug use
3. Hemophilia
4. Male sexual partner
5. Sexual partner in HIV/AIDS high risk group
6. More than 5 sexual partners within the last 6 months
7. Personal history of sexually transmissible disease (in the last 6 months)
8. Sexual partner with history of sexually transmissible disease (within the last 6 months)
9. Adoption
10. Family history of certain genetic conditions
11. Carrier of certain genetic conditions (Genetic screening will be performed)
12. Use of illegal drugs (Random drug screens may be performed)
13. Excessive use of alcohol
14. Certain medical conditions

Ovarian Stimulation
To prepare a woman's body for the assisted reproductive technologies described here, various hormonal medications are used to stimulate the development of ovarian follicles (fluid-filled sac in the ovary containing the egg). This is known as "superovulation." The idea is to bring to maturity as many eggs as possible. The greater the number of eggs, the greater the chance for fertilization to occur. These medications are administered for seven to ten days and patients are carefully monitored. When follicular development has reached the stage where an optimum number of eggs will be produced with no untoward effects, another hormone, hCG, is administered. This triggers ovulation. Egg retrieval will be scheduled within 34 to 36 hours after hCG administration. The side effects of these medications most commonly reported include allergic sensitivity and pain, irritation or swelling at the injection site. In severe cases, additional symptoms may require hospitalization of the patient.

Egg Recovery
The most commonly used procedure for removing eggs from the ovaries is ultrasound-directed needle aspiration. This is a minor surgical procedure and can be performed under local anesthesia. A vaginal transducer (part of the ultrasound system) is placed in the vagina. An aspiration needle is inserted alongside the transducer and through the upper part of the vagina directly into the ovary. The ultrasound image allows the physician to accurately guide the needle to the ovary and into a mature follicle. The fluid contained in the follicle is withdrawn and deposited into a test tube. The collapsed follicle is re-inflated with a solution which is also aspirated into a test tube. These flushings are examined immediately in the lab to determine if an egg has been retrieved. If not, the process is repeated until an egg is obtained. The physician then moves on to the next follicle and repeats the process until all or an optimum number of eggs have been retrieved.

Eggs and sperm used for most of the alternative reproductive technologies are collected in this manner. With the exception of ICSI and GIFT, the extracted eggs are combined with sperm cells in a laboratory dish and placed in an incubator. The eggs are examined several hours later to verify fertilization. The embryos are now ready for transfer to the mother.

In Vitro Fertilization-Embryo Transfer (IVF-ET) Two days after egg retrieval, the embryos are ready to be transferred to a woman's uterus. The embryos are now removed from the incubator and loaded into a small catheter. The catheter is passed through the woman's cervix and into her uterus. Once the catheter is correctly positioned, the embryos are gently expelled into the uterus. IVF may be used in a case where a woman's fallopian tubes are either normal, blocked, abnormal, or absent. Her partner may have normal or reduced sperm counts. It is often employed by couples whose fertilization problems cannot be identified.

47. The process of In Vitro Fertilization: sperm are combined with extracted eggs. Resulting embryos are inserted into the uterus

Aspiration and Irrigation Needle
Eggs are retrieved from fluid-filled ovarian follicles with this needle. Each follicle is punctured with the needle and the follicular fluid and eggs are removed from the follicle with gentle suction. Ultrasound images of the needle and ovaries enables the physician to retrieve eggs without surgery.

Laparoscopic Catheter
The laparoscopic catheter is used for transfer of eggs and sperm (GIFT) or fertilized embryos (PROST or ZIFT) to the fallopian tubes. An embryologist uses a syringe to draw embryos or eggs and sperm into the end of the catheter. Once the physician confirms that the catheter is placed in the fallopian tube, the embryos or eggs and sperm are expelled from the catheter.

Intrauterine Insemination and Transcervical Embryo Transfer Catheter
Sperm (Intrauterine Insemination) or embryos (Embryo Transfer) are drawn up into the end of this small catheter. The catheter is passed through the cervix and the sperm or embryos are expelled into the uterus.

Cryovials
Millions of healthy, swimming sperm can be frozen and stored for several years in a single cryovial. The vials are stored in liquid nitrogen -320.8 degrees Fahrenheit (-196 degrees Celsius). Up to half of the swimming sperm are still motile after the cryovial is thawed.

Cryostraws
Embryos and fluid are loaded into the cryostraw and both ends of the straw are sealed prior to freezing. Frozen embryos can be stored in liquid nitrogen -320.8 degrees Fahrenheit (-196 degrees Celsius) for several years.

Petri Dishes and Test Tubes
Babies born from in vitro fertilization procedures are frequently called "test tube babies." Test tubes were used for many of the early in vitro fertilization procedures. Today, petri dishes are preferred by most embryologists for incubation of the eggs and sperm or embryos.

Pipettes
Sterile, hand-drawn glass pipettes are used to transfer embryos and eggs to petri dishes. The inner diameter of the pipette is approximately 0.200 millimeters.

Micromanipulation Pipettes
The test tubes with green caps each hold a single pipette that is used for manipulation of eggs, sperm, or embryos. Pipette inner diameter sizes range from 0.005 millimeters (sperm injection) to 0.030 millimeters (egg or embryo-holding pipette).

Assisted Fertilization
Assisted fertilization is needed for sperm that fail to fertilize the egg or for couples that do not have enough sperm for traditional in vitro fertilization. Intracytoplasmic Sperm Injection (ICSI) is the newest and most promising micromanipulation technique for assisted fertilization. This technique involves picking up a single sperm and injecting it directly into the egg. Over 400 babies worldwide have been born as a result of ICSI. The first UIHC IVF Program "ICSI babies" were born November 1994.