Transit of Venus: Venus will pass across the face of the sun, producing a silhouette that no one alive today will likely see again

On June 5th, 2012, Venus will pass across the face of the sun, producing a silhouette that no one alive today will likely see again.

Transits of Venus are very rare, coming in pairs separated by more than a hundred years. This June's transit, the bookend of a 2004-2012 pair, won't be repeated until the year 2117. Fortunately, the event is widely visible. Observers on seven continents, even a sliver of Antarctica, will be in position to see it.

The nearly 7-hour transit begins at 3:09 pm Pacific Daylight Time (22:09 UT) on June 5th. The timing favors observers in the mid-Pacific where the sun is high overhead during the crossing.  In the USA, the transit will at its best around sunset. That's good, too. Creative photographers will have a field day imaging the swollen red sun "punctured" by the circular disk of Venus.

Observing tip: Do not stare at the sun. Venus covers too little of the solar disk to block the blinding glare.  Instead, use some type of projection technique or a solar filter. A #14 welder's glass is a good choice.  Many astronomy clubs will have solar telescopes set up to observe the event; contact your local club for details. 

The June 8, 2004, transit of Venus photographed by Frans Snik at the Dutch Open Telescope in La Palma, Canary Islands. 

Transits of Venus first gained worldwide attention in the 18^thcentury.  In those days, the size of the solar system was one of the biggest mysteries of science.   The relative spacing of planets was known, but not their absolute distances. How many miles would you have to travel to reach another world?  The answer was as mysterious then as the nature of dark energy is now.

Venus was the key, according to astronomer Sir Edmund Halley. He realized that by observing transits from widely-spaced locations on Earth it should be possible to triangulate the distance to Venus using the principles of parallax.

The idea galvanized scientists who set off on expeditions around the world to view a pair of transits in the 1760s.  The great explorer James Cook himself was dispatched to observe one from Tahiti, a place as alien to 18^th-century Europeans as the Moon or Mars might seem to us now.  Some historians have called the international effort the "the Apollo program of the 18^th century."

In retrospect, the experiment falls into the category of things that sound better than they actually are.  Bad weather, primitive optics, and the natural "fuzziness" of Venus’s atmosphere prevented those early observers from gathering the data they needed.  Proper timing of a transit would have to wait for the invention of photography in the century after Cook’s voyage.  In the late 1800s, astronomers armed with cameras finally measured the size of the Solar System as Edmund Halley had suggested.

A double transit: the ISS+Venus on June 8, 2004. Photo credit: Tomas Maruska of Stupava, Slovakia 

This year’s transit is the second of an 8-year pair. Anticipation was high in June 2004 as Venus approached the sun.  No one alive at the time had seen a Transit of Venus with their own eyes, and the hand-drawn sketches and grainy photos of previous centuries scarcely prepared them for what was about to happen.  Modern solar telescopes captured unprecedented view of Venus’s atmosphere backlit by solar fire.  They saw Venus transiting the sun’s ghostly corona, and gliding past magnetic filaments big enough to swallow the planet whole.  One photographer even caught a spaceship, the International Space Station, transiting the sun alongside Venus. 

2012 should be even better as cameras and solar telescopes have improved. Moreover, NASA’s Solar Dynamics Observatory is going to be watching too. SDO will produce Hubble-quality images of this rare event.

All about leishmaniasis - part 4: Treatment, prevention and control of Kala Azar

Treatment of Leishmaniasis

The treatment of leishmaniasis depends on the form of the disease (cutaneous, mucocutaneous, or visceral), and may be in the form of tablets or injections. Cutaneous leishmaniasis sometimes heals on its own and may not require treatment.

Patients should consult with their primary health care provider. Some patients may be referred to a specialist, such as a dermatologist or infectious disease specialist. Your health care provider can talk with CDC staff about whether and how you should be treated.

Prevention & Control

The best way for travelers to prevent infection is to protect themselves from sand fly bites. To decrease the risk of being bitten:

Avoid outdoor activities, especially from dusk to dawn, when sand flies generally are the most active.

When outdoors (or in unprotected quarters):

• Minimize the amount of exposed skin. To the extent that is tolerable in the climate, wear long-sleeved shirts, long pants, and socks; and tuck your shirt into your pants.
• Apply insect repellent to exposed (uncovered) skin and under the ends of sleeves and pant legs. Follow the instructions on the label of the repellent. The most effective repellents are those that contain the chemical DEET (N,N-diethylmetatoluamide).

Note:

Bed nets, repellents, and insecticides should be purchased before traveling and can be found in hardware, camping, and military surplus stores.

When indoors:

• Stay in well-screened or air-conditioned areas.
• Keep in mind that sand flies are much smaller than mosquitoes and therefore can get through smaller holes.
• Spray living/sleeping areas with an insecticide to kill insects.
• If you are not sleeping in a well-screened or air-conditioned area, use a bed net and tuck it under your mattress. If possible, use a bed net that has been soaked in or sprayed with a pyrethroid-containing insecticide (permethrin or deltamethrin). The same treatment can be applied to screens, curtains, sheets, and clothing (clothing should be retreated after five washings).

All about Leishmaniasis part 3: Diagnosis of Kala Azar

Diagnosis of Leishmaniasis

Bone marrow biopsy specimen from a patient with visceral leishmaniasis showing a macrophage containing Leishmaniaamastigotes. CDC photo.

Diagnosis of visceral leishmaniasis may require taking a blood sample and/or taking a biopsy from the bone marrow to show the parasite. Diagnosis of cutaneous leishmaniasis will require a small biopsy or scraping of the ulcer. Diagnosis of mucocutaneous leishmaniasis requires a biopsy of the affected tissues.  

Biopsy samples are examined by microscopy, culture and other methods to look for the parasite and identify the specific kind of Leishmania causing the ulcer. Some of these methods will give results within a few days, but culture may take 2-4 weeks to demonstrate the parasite.

All about leishmaniasis - part 2: Kala azar disease manifestations

Leishmaniasis Disease

• The most common form of leishmaniasis is localized cutaneous leishmaniasis (CL), which usually appears as one or more painless ulcers.   
• Visceral leishmaniasis (VL) is a febrile illness with weight loss, enlargement of the spleen and liver, and decreases in the production of blood cells that can lead to anemia, bleeding and infections with other microorganisms. Without treatment, this form of the disease is nearly always fatal.
• Mucocutaneous leishmaniasis is a rare form of the disease that can occur months or years after the healing of a CL ulcer. This form of the disease can affect the nasal septum, palate and other parts of the nasopharynx.

Typical New World cutaneous leishmaniasis ulcer. Photo: B. Arana, MERTU, Guatemala.

Marked enlargement of the spleen typical of visceral leishmaniasis in a patient in lowland Nepal. Photo: C. Bern, CDC.

What is Leishmaniasis? Everything you ever wanted to know about Kala Azar

Image: A Phlebotomus papatasi sand fly that transmits one type of leishmaniasis, next to an image of Leishmania sp. promastigotes from culture. This is the stage of the parasite that occurs inside the mid-gut of the sand fly.

Leishmaniasis includes two major diseases, cutaneous leishmaniasis and visceral leishmaniasis, caused by more than 20 different leishmanial species.

Cutaneous leishmaniasis, the most common form of the disease, causes skin ulcers. Visceral leishmaniasis causes a severe systemic disease that is usually fatal without treatment. Mucocutaneous leishmaniasis is a rare but severe form affecting the nasal and oral mucosa.

Leishmaniasis is transmitted by the bite of small insects called sand flies. Many leishmanial species infect animals as well as humans. The distribution is world-wide, but 90% of visceral leishmaniasis cases occur in India, Bangladesh, Nepal, Sudan, Ethiopia and Brazil, while 90% of cutaneous leishmaniasis cases occur in Afghanistan, Algeria, Iran, Saudi Arabia, Syria, Brazil, Colombia, Peru and Bolivia.

Leishmaniasis FAQs

What is leishmaniasis?

Leishmaniasis is a parasitic disease that is found in parts of the tropics, subtropics, and southern Europe. Leishmaniasis is caused by infection with Leishmania parasites, which are spread by the bite of infected sand flies. There are several different forms of leishmaniasis in people. The most common forms arecutaneous leishmaniasis, which causes skin sores, and visceral leishmaniasis, which affects several internal organs (usually spleen, liver, and bone marrow).

What are the signs and symptoms of cutaneous leishmaniasis?

People who have cutaneous leishmaniasis have one or more sores on their skin. The sores can change in size and appearance over time. The sores may start out as bumps or nodules, and may end up as ulcers (like a volcano, with a raised edge and central crater). Some leishmaniasis ulcers are covered by a scab. They can be painless or painful. Some people have swollen glands near the sores (for example, under the arm if the sores are on the arm or hand).

What are the signs and symptoms of visceral leishmaniasis?

People who have visceral leishmaniasis usually have fever, weight loss, and an enlarged spleen and liver, and abnormal blood tests. People may have low blood counts, including a low red blood cell count (anemia), low white blood cell count, and low platelet count.

How common is leishmaniasis in the world?

The number of new cases of cutaneous leishmaniasis each year in the world is thought to be about 1.5 million. The number of new cases of visceral leishmaniasis is thought to be about 500,000.

In what parts of the world is leishmaniasis found?

In the New World (the Western Hemisphere), leishmaniasis is found in some parts of Mexico, Central America, and South America. It is not found in Chile or Uruguay.

In the Old World (the Eastern Hemisphere), leishmaniasis is found in some parts of Asia, the Middle East, Africa, and southern Europe. It is not found in Australia or the Pacific Islands.

Overall, leishmaniasis is found in specific areas of about 88 countries. Some of these countries account for most of the world’s cases of leishmaniasis:

• Over 90 percent of the cases of cutaneous leishmaniasis occur in parts of Afghanistan, Algeria, Iran, Iraq, Saudi Arabia, and Syria (in the Old World) and in Brazil and Peru (in the New World);
• Over 90 percent of the cases of visceral leishmaniasis occur in parts of India, Bangladesh, Nepal, Sudan, and Brazil.

Cases of leishmaniasis evaluated in the United States reflect travel and immigration patterns. For example, cases in U.S. civilian travelers typically are cases of cutaneous leishmaniasis acquired in common tourist destinations in Latin America. U.S. military personnel have become infected with leishmaniasis in Iraq and Afghanistan.

How do people get infected with Leishmania parasites?

The main route is through the bite of infected female phlebotomine sand flies. Sand flies become infected by sucking blood from an infected animal or person. People might not realize that sand flies are present because:

• They do not make noise when they fly;
• They are small: they are only about one-third the size of typical mosquitoes or even smaller;
• Their bites might not be noticed (the bites may be painless or painful).

Sand flies usually are most active in twilight, evening, and night-time hours (from dusk to dawn). Although sand flies are less active during the hottest time of the day, they may bite if they are disturbed (for example, if a person brushes up against the trunk of a tree or other site where sand flies are resting).

Some types (species) of Leishmania parasites may also be spread by blood transfusions or contaminated needles (needle sharing). Congenital transmission (spread from a pregnant woman to her baby) has been reported.

Who is at risk for Leishmania infection?

People of all ages are at risk for infection if they live or travel where leishmaniasis is found. Leishmaniasis usually is more common in rural than in urban areas; but it is found in the outskirts of some cities. The transmission risk is highest from dusk to dawn because this is when sand flies generally are the most active. Examples of people who may have an increased risk for infection include adventure travelers, ecotourists, Peace Corps volunteers, missionaries, soldiers, ornithologists (people who study birds), and other people who do research (or are active) outdoors at night/twilight.

If I were bitten by an infected sand fly, when would leishmaniasis develop?

The skin sores of cutaneous leishmaniasis usually develop within a few weeks or months of the sand fly bite.

People with visceral leishmaniasis usually become sick within months (sometimes as long as years) of when they were bitten.

What should I do if I think I might have leishmaniasis?

See your health care provider. Be sure to say where you have traveled and to mention the possibility of leishmaniasis.

How is leishmaniasis diagnosed?

The first steps are to check if you have been in a part of the world where leishmaniasis is found and if you have any signs or symptoms that might be from leishmaniasis.

Samples of tissue (for example, from skin sores) can be examined for the parasite under a microscope, in cultures, and through other means.

Blood tests that detect antibody (an immune response) to the parasite can be helpful for cases of visceral leishmaniasis; tests to look for the parasite itself usually are done also.

CDC staff can advise your health care provider and can help with the laboratory testing. Diagnosing leishmaniasis can be difficult. Sometimes the laboratory tests are negative even if a person has leishmaniasis.

Does leishmaniasis have to be treated?

                 

The skin sores of cutaneous leishmaniasis often heal on their own without treatment. But this can take months or even years, and the sores can leave ugly scars. Another potential concern applies to some (not all) types of the parasite found in South and Central America: occasionally, the parasite spreads from the skin to the nose or mouth and causes sores there (mucocutaneous leishmaniasis). Mucocutaneous leishmaniasis might not be noticed until years after the original skin sores healed. The best way to prevent mucocutaneous leishmaniasis is to ensure adequate treatment of the cutaneous infection.

If not treated, severe (advanced) cases of visceral leishmaniasis can cause death.

I plan to travel to an area of the world where leishmaniasis is found. What can I do to prevent infection?

No vaccines or drugs to prevent infection are available. The best way for travelers to prevent infection is to protect themselves from sand fly bites. To decrease the risk of being bitten:

Avoid outdoor activities, especially from dusk to dawn, when sand flies generally are the most active.

When outdoors (or in unprotected quarters):

• Minimize the amount of exposed skin. To the extent that is tolerable in the climate, wear long-sleeved shirts, long pants, and socks; and tuck your shirt into your pants.
• Apply insect repellent to exposed skin and under the ends of sleeves and pant legs. Follow the instructions on the label of the repellent. The most effective repellents are those that contain the chemical DEET (N,N-diethylmetatoluamide).

When indoors:

• Stay in well-screened or air-conditioned areas.
• Keep in mind that sand flies are much smaller than mosquitoes and therefore can get through smaller holes.
• Spray living/sleeping areas with an insecticide to kill insects.
• If you are not sleeping in a well-screened or air-conditioned area, use a bed net and tuck it under your mattress. If possible, use a bed net that has been soaked in or sprayed with a pyrethroid-containing insecticide (permethrin or deltamethrin). The same treatment can be applied to screens, curtains, sheets, and clothing (clothing should be retreated after five washings).

NOTE:

Bed nets, repellents, and insecticides should be purchased before traveling and can be found in hardware, camping, and military surplus stores.

If I have already had leishmaniasis, could I get it again?

Yes. Some people have had cutaneous leishmaniasis more than once. Therefore, you should follow the preventive measures listed above whenever you are in an area where leishmaniasis is found.

Infertility FAQ's: All that you want to know about infertility, its management and treatment

Infertility FAQ's

• What is infertility?
• Is infertility a common problem?
• Is infertility just a woman's problem?
• What causes infertility in men?
• What increases a man's risk of infertility?
• What causes infertility in women?
• What things increase a woman's risk of infertility?
• How does age affect a woman's ability to have children?
• How long should women try to get pregnant before calling their doctors?
• How will doctors find out if a woman and her partner have fertility problems?
• How do doctors treat infertility?
• What medicines are used to treat infertility in women?
• What is intrauterine insemination (IUI)?
• What is assisted reproductive technology (ART)?
• How often is assisted reproductive technology (ART) successful?
• What are the different types of assisted reproductive technology (ART)?

What is infertility?

Infertility means not being able to get pregnant after one year of trying. Or, six months, if a woman is 35 years of age or older. Women who can get pregnant but are unable to stay pregnant may also be infertile.

Pregnancy is the result of a process that has many steps. To get pregnant—

• A woman’s body must release an egg from one of her ovaries (ovulation).
• The egg must go through a fallopian tube toward the uterus (womb).
• A man's sperm must join with (fertilize) the egg along the way.
• The fertilized egg must attach to the inside of the uterus (implantation).

Infertility can happen if there are problems with any of these steps.

Is infertility a common problem?

Yes. About 10 % of women (6.1 million) in the United States ages 15–44 years have difficulty getting pregnant or staying pregnant.

Is infertility just a woman's problem?

No, infertility is not always a woman's problem. Both women and men can have problems that cause infertility. About one-third of infertility cases are caused by women’s problems. Another one third of fertility problems are due to the man. The other cases are caused by a mixture of male and female problems or by unknown problems.

What causes infertility in men?

Infertility in men is most often caused by—

• A problem called varicocele (VAIR-ih-koh-seel). This happens when the veins on a man’s testicle(s) are too large. This heats the testicles. The heat can affect the number or shape of the sperm.
• Other factors that cause a man to make too few sperm or none at all.
• Movement of the sperm. This may be caused by the shape of the sperm. Sometimes injuries or other damage to the reproductive system block the sperm.

Sometimes a man is born with the problems that affect his sperm. Other times problems start later in life due to illness or injury. For example, cystic fibrosis often causes infertility in men.

What increases a man's risk of infertility?

A man's sperm can be changed by his overall health and lifestyle. Some things that may reduce the health or number of sperm include—

• Heavy alcohol use
• Drugs
• Smoking cigarettes
• Age
• Environmental toxins, including pesticides and lead
• Health problems such as mumps, serious conditions like kidney disease, or hormone problems
• Medicines
• Radiation treatment and chemotherapy for cancer

What causes infertility in women?

Most cases of female infertility are caused by problems with ovulation. Without ovulation, there are no eggs to be fertilized. Some signs that a woman is not ovulating normally include irregular or absent menstrual periods.

Ovulation problems are often caused by polycystic ovarian syndrome (PCOS). PCOS is a hormone imbalance problem which can interfere with normal ovulation. PCOS is the most common cause of female infertility. Primary ovarian insufficiency (POI) is another cause of ovulation problems. POI occurs when a woman’s ovaries stop working normally before she is 40. POI is not the same as early menopause.

Less common causes of fertility problems in women include—

• Blocked fallopian tubes due to pelvic inflammatory disease, endometriosis, or surgery for an ectopic pregnancy
• Physical problems with the uterus
• Uterine fibroids, which are non-cancerous clumps of tissue and muscle on the walls of the uterus

What things increase a woman's risk of infertility?

Many things can change a woman's ability to have a baby. These include—

• Age
• Smoking
• Excess alcohol use
• Stress
• Poor diet
• Athletic training
• Being overweight or underweight
• Sexually transmitted infections (STIs)
• Health problems that cause hormonal changes, such as polycystic ovarian syndrome andprimary ovarian insufficiency

How does age affect a woman's ability to have children?

Many women are waiting until their 30s and 40s to have children. In fact, about 20% of women in the United States now have their first child after age 35. So age is a growing cause of fertility problems. About one-third of couples in which the woman is older than 35 years have fertility problems.

Aging decreases a woman's chances of having a baby in the following ways—

• Her ovaries become less able to release eggs
• She has a smaller number of eggs left
• Her eggs are not as healthy
• She is more likely to have health conditions that can cause fertility problems
• She is more likely to have a miscarriage

How long should women try to get pregnant before calling their doctors?

Most experts suggest at least one year. Women aged 35 years or older should see their doctors after six months of trying. A woman's chances of having a baby decrease rapidly every year after the age of 30.

Some health problems also increase the risk of infertility. So, women should talk to their doctors if they have—

• Irregular periods or no menstrual periods
• Very painful periods
• Endometriosis
• Pelvic inflammatory disease
• More than one miscarriage

It is a good idea for any woman to talk to a doctor before trying to get pregnant. Doctors can help you get your body ready for a healthy baby. They can also answer questions on fertility and give tips on conceiving.

How will doctors find out if a woman and her partner have fertility problems?

Doctors will do an infertility checkup. This involves a physical exam. The doctor will also ask for both partners’ health and sexual histories. Sometimes this can find the problem. However, most of the time, the doctor will need to do more tests.

In men, doctors usually begin by testing the semen. They look at the number, shape, and movement of the sperm. Sometimes doctors also suggest testing the level of a man's hormones.

In women, the first step is to find out if she is ovulating each month. There are a few ways to do this. A woman can track her ovulation at home by—

• Writing down changes in her morning body temperature for several months
• Writing down how her cervical mucus looks for several months
• Using a home ovulation test kit (available at drug or grocery stores)

Doctors can also check ovulation with blood tests. Or they can do an ultrasound of the ovaries. If ovulation is normal, there are other fertility tests available.

Some common tests of fertility in women include—

• Hysterosalpingography (HIS-tur-oh-sal-ping-GOGH-ru-fee): This is an X-ray of the uterus and fallopian tubes. Doctors inject a special dye into the uterus through the vagina. This dye shows up in the X-ray. Doctors can then watch to see if the dye moves freely through the uterus and fallopian tubes. This can help them find physical blocks that may be causing infertility. Blocks in the system can keep the egg from moving from the fallopian tube to the uterus. A block could also keep the sperm from reaching the egg.
• Laparoscopy (lap-uh-ROS-kuh-pee): A minor surgery to see inside the abdomen. The doctor does this with a small tool with a light called a laparoscope (LAP-uh-roh-skohp). She or he makes a small cut in the lower abdomen and inserts the laparoscope. With the laparoscope, the doctor can check the ovaries, fallopian tubes, and uterus for disease and physical problems. Doctors can usually find scarring and endometriosis by laparoscopy.

Finding the cause of infertility can be a long and emotional process. It may take time to complete all the needed tests. So don't worry if the problem is not found right away.

How do doctors treat infertility?

Infertility can be treated with medicine, surgery, artificial insemination, or assisted reproductive technology. Many times these treatments are combined. In most cases infertility is treated with drugs or surgery.

Doctors recommend specific treatments for infertility based on—

• Test results
• How long the couple has been trying to get pregnant
• The age of both the man and woman
• The overall health of the partners
• Preference of the partners

Doctors often treat infertility in men in the following ways—

• Sexual problems: Doctors can help men deal with impotence or premature ejaculation. Behavioral therapy and/or medicines can be used in these cases.
• Too few sperm: Sometimes surgery can correct the cause of the problem. In other cases, doctors surgically remove sperm directly from the male reproductive tract. Antibiotics can also be used to clear up infections affecting sperm count.
• Sperm movement: Sometimes semen has no sperm because of a block in the man’s system. In some cases, surgery can correct the problem.

In women, some physical problems can also be corrected with surgery.

A number of fertility medicines are used to treat women with ovulation problems. It is important to talk with your doctor about the pros and cons of these medicines. You should understand the possible dangers, benefits, and side effects.

What medicines are used to treat infertility in women?

Some common medicines used to treat infertility in women include—

• Clomiphene citrate (Clomid®): This medicine causes ovulation by acting on the pituitary gland. It is often used in women who have polycystic ovarian syndrome (PCOS) or other problems with ovulation. This medicine is taken by mouth.
• Human menopausal gonadotropin or hMG (Repronex®, Pergonal®): This medicine is often used for women who don't ovulate due to problems with their pituitary gland—hMG acts directly on the ovaries to stimulate ovulation. It is an injected medicine.
• Follicle-stimulating hormone or FSH (Gonal-F®, Follistim®): FSH works much like hMG. It causes the ovaries to begin the process of ovulation. These medicines are usually injected.
• Gonadotropin-releasing hormone (Gn-RH) analog: These medicines are often used for women who don't ovulate regularly each month. Women who ovulate before the egg is ready can also use these medicines. Gn-RH analogs act on the pituitary gland to change when the body ovulates. These medicines are usually injected or given with a nasal spray.
• Metformin (Glucophage®): Doctors use this medicine for women who have insulin resistance and/or PCOS. This drug helps lower the high levels of male hormones in women with these conditions. This helps the body to ovulate. Sometimes clomiphene citrate or FSH is combined with metformin. This medicine is usually taken by mouth.
• Bromocriptine (Parlodel®): This medicine is used for women with ovulation problems due to high levels of prolactin. Prolactin is a hormone that causes milk production.

Many fertility drugs increase a woman's chance of having twins, triplets, or other multiples. Women who are pregnant with multiple fetuses have more problems during pregnancy. Multiple fetuses have a high risk of being born too early (prematurely). Premature babies are at a higher risk of health and developmental problems.

What is intrauterine insemination (IUI)?

Intrauterine insemination (IUI) is an infertility treatment that is often called artificial insemination. In this procedure, the woman is injected with specially prepared sperm. Sometimes the woman is also treated with medicines that stimulate ovulation before IUI.

IUI is often used to treat—

• Mild male factor infertility
• Women who have problems with their cervical mucus
• Couples with unexplained infertility

What is assisted reproductive technology (ART)?

Assisted reproductive technology (ART) is a group of different methods used to help infertile couples. ART works by removing eggs from a woman's body. The eggs are then mixed with sperm to make embryos. The embryos are then put back in the woman's body.

How often is assisted reproductive technology (ART) successful?

Success rates vary and depend on many factors. Some things that affect the success rate of ART include—

• Age of the partners
• Reason for infertility
• Clinic
• Type of ART
• If the egg is fresh or frozen
• If the embryo is fresh or frozen

CDC collects success rates on ART for some fertility clinics. According to the CDC’s 2010 Preliminary ART Success Rates, the average percentage of ART cycles that led to a live birth were—

• 42% in women younger than 35 years of age
• 32% in women aged 35–37 years
• 22% in women aged 38–40 years
• 12% in women aged 41–42 years
• 5% in women aged 43–44 years

ART can be expensive and time-consuming. But it has allowed many couples to have children that otherwise would not have been conceived. The most common complication of ART is multiple fetuses. But this is a problem that can be prevented or minimized in several different ways.

What are the different types of assisted reproductive technology (ART)?

Common methods of ART include—

• In vitro fertilization (IVF) means fertilization outside of the body. IVF is the most effective ART. It is often used when a woman's fallopian tubes are blocked or when a man produces too few sperm. Doctors treat the woman with a drug that causes the ovaries to produce multiple eggs. Once mature, the eggs are removed from the woman. They are put in a dish in the lab along with the man's sperm for fertilization. After 3 to 5 days, healthy embryos are implanted in the woman's uterus.
• Zygote intrafallopian transfer (ZIFT) or Tubal Embryo Transfer is similar to IVF. Fertilization occurs in the laboratory. Then the very young embryo is transferred to the fallopian tube instead of the uterus.
• Gamete intrafallopian transfer (GIFT) involves transferring eggs and sperm into the woman's fallopian tube. So fertilization occurs in the woman's body. Few practices offer GIFT as an option.
• Intracytoplasmic sperm injection (ICSI) is often used for couples in which there are serious problems with the sperm. Sometimes it is also used for older couples or for those with failed IVF attempts. In ICSI, a single sperm is injected into a mature egg. Then the embryo is transferred to the uterus or fallopian tube.

ART procedures sometimes involve the use of donor eggs (eggs from another woman), donor sperm, or previously frozen embryos. Donor eggs are sometimes used for women who can not produce eggs. Also, donor eggs or donor sperm is sometimes used when the woman or man has a genetic disease that can be passed on to the baby. An infertile woman or couple may also use donor embryos. These are embryos that were either created by couples in infertility treatment or were created from donor sperm and donor eggs. The donated embryo is transferred to the uterus. The child will not be genetically related to either parent.

Surrogacy

Women with no eggs or unhealthy eggs might also want to consider surrogacy. A surrogate is a woman who agrees to become pregnant using the man's sperm and her own egg. The child will be genetically related to the surrogate and the male partner. After birth, the surrogate will give up the baby for adoption by the parents.

Gestational Carrier

Women with ovaries but no uterus may be able to use a gestational carrier. This may also be an option for women who shouldn't become pregnant because of a serious health problem. In this case, a woman uses her own egg. It is fertilized by the man's sperm and the embryo is placed inside the carrier's uterus. The carrier will not be related to the baby and gives him or her to the parents at birth.

Recent research by the Centers for Disease Control showed that ART babies are two to four times more likely to have certain kinds of birth defects. These may include heart and digestive system problems, and cleft (divided into two pieces) lips or palate. Researchers don’t know why this happens. The birth defects may not be due to the technology. Other factors, like the age of the parents, may be involved. More research is needed. The risk is relatively low, but parents should consider this when making the decision to use ART.