Posts Tagged ‘ultrasound’

Concerns about fifth disease

Tuesday, March 27th, 2012

We get questions about fifth disease from time to time. It’s a common childhood illness that’s usually pretty mild, but if you get infected during pregnancy, it may hurt your baby. The good news is that about 6 in 10 adults (60 percent) had the infection as children and if you’ve already had fifth disease, you can’t get it again.  Nonetheless, about 1 in 400 women in the United States gets infected with fifth disease during pregnancy.

Fifth disease is caused by a virus called parvovirus B19. (It’s called fifth disease because many years ago, it appeared fifth in a list of common causes of childhood rash and fever.) It usually spreads through the air from an infected person’s cough or sneeze. People with young children and who work with children (such as child care providers and teachers) are most likely to come in contact with fifth disease and get infected. You can read about symptoms in children and adults at this link.

Most unborn babies are not harmed if their mother gets fifth disease. But some babies do become infected. The virus can make it hard for babies to make red blood cells, which can lead to a dangerous form of anemia, heart failure, miscarriage, or stillbirth.

You can protect yourself from getting infected by washing your hands well after being around children. Be sure to carefully throw away tissues used by children, and don’t share drinking glasses, cups, forks or other utensils with anyone who has fifth disease or who is in contact with someone who has fifth disease.

If you’re pregnant and become infected, your health care provider monitors your pregnancy carefully for problems with your baby. He may recommend that you have an ultrasound once a week or every other week for 8 to 12 weeks. If ultrasound doesn’t show any problems, you don’t need any more testing.  If an ultrasound shows that your baby is having problems, your provider may recommend amniocentesis to confirm the infection. If your baby has fifth disease, chances are the infection will go away on its own. Your provider may monitor your baby’s health during routine prenatal care visits.

While there is no treatment for fifth disease, there may be treatment options for problems caused in a developing baby. In rare cases of severe anemia, sometimes a provider can treat it by giving the baby a blood transfusion through the umbilical cord. If hydrops, a build up of fluid in the baby’s body, forms in the third trimester, the baby is sometimes induced and born early to receive treatment.

Again, the majority of pregnant women do not get fifth disease and, if they do, their babies are not harmed. But if you work in a day care center or are around school aged children a lot, it’s good to know about fifth disease and how to protect yourself.

Fetal growth restriction

Monday, February 6th, 2012

insideBabies who are smaller than most other babies of the same gestational age may be called growth-restricted, small-for-gestational age or small-for-date. These babies may be born premature (before 37 completed weeks of pregnancy) or born full term but small. Some of these babies are healthy and are small simply because their parents are smaller than average. Others have low birthweight because something slowed or stopped their growth in the uterus.

About 10 percent of babies are growth-restricted. The good news is that there are steps a pregnant woman can take to help avoid factors that may contribute to premature birth and/or fetal growth restriction. Those factors include:

Placental problems. These can reduce the flow of blood and nutrients to the baby, limiting growth.

– Birth defects. Babies with certain birth defects are more likely to be growth restricted. Also, babies with birth defects are more likely to be born prematurely.

– Previous birth of a growth-restricted baby. This may increase the risk by about 50 percent in another pregnancy.

– Chronic health conditions in the mother. High blood pressure, diabetes, and heart, lung and kidney problems sometimes can reduce birthweight.

Smoking. Pregnant women who smoke cigarettes are nearly twice as likely to have a low-birthweight baby as women who do not smoke. Smoking slows the baby’s growth and increases the risk of premature delivery.

Alcohol and illicit drugs.  These may limit the baby’s growth, increase the risk of premature delivery and cause birth defects.

Infections in the fetus. Certain viral and parasitic infections, including cytomegalovirus, rubella, chickenpox and toxoplasmosis, can slow the baby’s growth and cause birth defects.

Inadequate maternal weight gain. Women who don’t gain enough weight during pregnancy increase their risk of having a low-birthweight baby.

A health care provider may suspect fetal growth restriction if the mother’s uterus is not growing at a normal rate. He can help confirm this with a series of ultrasounds that monitor how quickly the baby is growing. The provider closely monitors the well-being of a growth-restricted fetus using ultrasound and fetal heart rate monitoring. He also may use a form of ultrasound called Doppler to measure blood flow in the umbilical cord and certain fetal blood vessels. If these tests show that the baby is having problems, the provider may recommend early delivery. In severe cases, this can help prevent stillbirth and newborn health problems.

It is possible that growth restriction before birth may result in problems in adulthood. It may cause lasting changes in certain insulin-sensitive organs like the liver, skeletal muscles and pancreas. Before birth, these changes may help the malnourished fetus use all available nutrients. However, after birth these changes may contribute to some health problems.

The March of Dimes has funded research in the area of fetal growth restriction. Grantees are investigating the role of certain genes in fetal growth restriction, as a step toward developing treatment to prevent this problem or improve the growth of affected babies.

The March of Dimes also promotes the health benefits of smoking prevention and cessation by providing educational materials for consumers  and supporting projects that increase smoking-cessation services available to pregnant women who smoke. Women who quit smoking, avoid alcohol and drugs, control chronic medical conditions and maintain a healthy weight during their pregnancy are doing a great deal to help prevent fetal growth restriction.

3-D and 4-D ultrasound

Wednesday, March 2nd, 2011

In 3-D ultrasound, sound waves are scanned across the abdomen to offer three dimensional images that are similar to photographs. 3-D ultrasound images help provide a clearer picture of the baby’s development and can detect facial abnormalities, such as cleft lip or palate, or the extent of a neural tube defect, like spina bifida.

You may have heard of 4-D ultrasound, which is a combination of 3-D still images viewed over time. The result is “live action” images of your developing baby.  It is not available everywhere and is used to take a more in depth view of an image seen in a previous ultrasound. As with other types of ultrasound, it is helpful in analyzing the baby’s age and development. It can detect structural problems with the uterus, placental placement or abnormalities, abnormal bleeding, ectopic pregnancy, fibroids and ovarian tumors. Many high-risk pregnancy centers have this sophisticated, higher resolution technology.

4-D sounds really cool, but it’s important to note that non-medical use of ultrasound during pregnancy should be avoided… no home videos for the sake of sharing your good news. Commercial sites, often unsupervised by physicians, may offer really fun looking “keepsake” fetal images to parents. Be aware, however, that the persons performing these ultrasounds may not have adequate training and may give a woman inaccurate or even harmful information.  So, if you’re really curious, speak with your provider about ultrasound options available to you.

Targeted or advanced ultrasound

Tuesday, March 1st, 2011

A targeted or advanced ultrasound usually follows after a standard ultrasound if the provider has seen something questionable and wants to take a closer look at it. This exam is more thorough than a standard ultrasound and can take from 30 minutes to a couple of hours. Among other things, it provides a more detailed view of the baby’s head and spine and is 95% effective in diagnosing neural tube defects like spina bifida. It includes a full body scan measuring all of the long bones, identifying major organs, including the heart and brain, nose and mouth.

Doppler imaging is a technique that can measure tiny changes occurring within the body, such as the speed and direction of blood flow. Sound waves bounce off moving red blood cells and produce an image of blood flow, something a standard ultrasound cannot do. Women with high blood pressure may receive an ultrasound with Doppler imaging of the umbilical artery to see if the blood flow to the baby or placenta is as it should be or if it is being compromised in some way.

Fetal echocardiography uses ultrasound to take a closer look at a developing baby’s heart. It offers a far more detailed view of the heart and provides information about its structure and rhythm. Women who are at increased risk of having a baby with a congenital heart defect may be offered this scan. It can provide valuable information about the anatomy and function of different parts of the heart, such as the valves, and is often used to rule out a possible problem rather than find one. If a heart defect is found, further body scanning for other possible defects will be recommended. Problems with fetal heart rhythms can be treated during pregnancy but structural defects require treatment, possibly surgery, after the baby is born. Knowing about a heart defect in advance will help ensure the baby is born in a medical center equipped to perform specialized medical treatment on the baby shortly after birth.

Ultrasound options

Monday, February 28th, 2011

Over the next couple of days, I’m going to write about ultrasound.  There are different types that are used for different purposes and I’ll review them.

Ultrasonography is the most commonly used tool for viewing a developing fetus. Ultrasound has been safely utilized for over 40 years, but only specially trained technicians and providers should perform an ultrasound, and only for medically necessary reasons.

Using sound waves to bounce off curves and shapes within your body, technicians are able to translate light and dark patterns into images of internal organs or a developing fetus. Standard ultrasound creates a 2-D image of a developing baby in mom’s womb. A woman may have a standard ultrasound during the first trimester to confirm and date the pregnancy (or to find out if she’s having twins like her mother did!)  But not all providers offer it that early in pregnancy, so don’t be upset if yours doesn’t. It also can be used to check the positioning of the placenta or level of amniotic fluid later on.

Most providers request an ultrasound between 18 and 20 weeks. The procedure lasts about 20 minutes and can be performed abdominally (by moving a transducer over the belly) or vaginally (using a slender wand-like device that is placed inside the vagina). A full bladder acts like a mirror and helps the technician get a clearer view, hence the recommendation of drinking a few glasses of water before the procedure.  This is great for the tech, but might get slightly squirmy for mom after a while.

Tomorrow’s post – What’s Doppler imaging (nope, not part of the weather report) and fetal echocardiography?

Choroid plexus cysts

Friday, December 3rd, 2010

Sometimes technology can be a double-edged sword.  For instance, we all love seeing those first ultrasound pictures of our babies—it is so exciting and amazing!  But ultrasound can also show us things that may or may not have consequences.  Choroid plexus cysts are an example.

The choroid plexus is the area of the brain that produces the fluid that surrounds the brain and spinal cord. This is not an area of the brain that involves learning or thinking. Occasionally, one or more cysts can form in the choroid plexus. These cysts are made of blood vessels and tissue. They aren’t a problem by themselves and they do not cause developmental delays or learning problems.

Using ultrasound, a health care provider can see these cysts in about 1 in 120 pregnancies at 15 to 20 weeks gestation. Most disappear during pregnancy or within several months after birth and are no risk to the baby.

However, if choroid plexus cysts are present and maternal blood testing (such as the quad screen) and/or the ultrasound itself shows other signs of risk, together it may all indicate a possible genetic defect. In this case, testing with higher-level ultrasound and amniocentesis may be offered to confirm or rule out serious problems.

Hearing your baby has choroid plexus cysts can be scary but don’t panic.  Just remember that most of the time this is a benign finding and does not mean that there is a problem.

Do those blood tests confuse you?

Monday, August 9th, 2010

For those of you who are pregnant, sometime between 15-20 weeks of pregnancy, you will be offered maternal serum screening.  What is this?  And more importantly, what do the results mean?  I think maternal blood screening is one of the most misunderstood tests in pregnancy.  And for some women it can be a very nerve-wracking experience.

The American College of Obstetricians and Gynecologists (ACOG) recommends that all pregnant women regardless of age be offered a screening test for Down syndrome and certain other birth defects.  This is a blood test that looks at the levels of either 3 or 4 (depending on the test) chemicals that are present in a pregnant woman’s blood.  The chemicals are AFP (alpha fetoprotein), hCG (human chorionic gonadotropin—the same chemical that a home pregnancy test measures), estriol, and recently most labs have added a fourth substance, inhibin A.  These chemicals are present in every pregnant woman’s blood.  Some of them are produced by the fetus while others are hormones produced by the placenta.

Maternal serum tests such as the triple screen or the quad screen as they are commonly called, look at the levels of these 3 or 4 chemicals in the mother’s blood and the woman’s age, weight, race, number of fetuses (e.g. twins) and whether she has diabetes that requires insulin treatment.  Then given all of those factors and the levels of the 3 or 4 chemicals the laboratory can determine the chance that a woman has a baby with Down syndrome, a neural tube defect (spina bifida), trisomy 18, or abdominal wall defects.

There are two different ways that the results may be reported.  A woman may receive her test result as a ratio. For example, her baby has a 1 in 500 chance for Down syndrome. Or, in some cases, a woman’s test results are reported as normal (screen negative) or abnormal (screen positive), depending on whether her results fall below or above a cut-off point (usually about 1 in 270).

The test is NOT a diagnosis of any of these conditions though.  This is where there is a lot of confusion.  By definition, screening tests do not diagnose a condition.  They only determine whether there is an increased risk for the condition.  The good news is that of all of the women who screen positive, only a small percentage will actually have a baby with one of these disorders.  Many times women have an abnormal result simply because their fetus is a few weeks older or younger than previously thought.

For women with abnormal results, the next step is usually an ultrasound. This test can check the gestational age of the fetus and show if a woman is carrying multiples. If either of these factors accounts for the abnormal test result, no further testing is needed. If ultrasound does not explain the abnormal test result, amniocentesis will be offered.  An amniocentesis is an invasive test where the doctor uses a needle to remove some of the amniotic fluid around the baby.  Although amnio does pose a very slight risk of miscarriage (1/4 of one percent or 1/500), it is extremely accurate and usually can give a pregnant woman a definitive answer.  Should a problem exist, arrangements can be made in advance for special care of the newborn at delivery.

Does a retroverted (tipped) uterus pose pregnancy risks?

Tuesday, August 3rd, 2010

Almost never. About 20 percent of women have a uterus that tips slightly backward. This is considered a normal variant of uterine positioning in most women.  It’s possible that some women may develop a retroverted uterus due to fibroids or scar tissue in the pelvis. Generally, the uterus straightens by early in the second trimester and does not contribute to pregnancy complications.

At about 12 weeks of pregnancy, the top of the uterus normally extends past the pelvic cavity. Rarely, a retroverted uterus may become trapped in the pelvis. This is called uterine incarceration and can cause pain and difficulty passing urine. An ultrasound can diagnose retroverted uterus in women with these symptoms. Simple treatments, including bladder drainage, positioning exercises the woman can do at home, or gentle manipulation by the health care provider, usually can restore the uterus to its normal position. Occasionally, an untreated incarcerated uterus may contribute to second-trimester miscarriage.

The placenta and fetal circulation

Thursday, January 14th, 2010

insideThe placenta is a remarkable organ that connects the mother’s blood supply with that of the developing fetus through the umbilical cord.  It transports oxygen and nutrients to the baby’s blood and returns the baby’s waste to the mom’s blood for disposal through her kidneys.

The placenta, formed from the same cells as the embryo, attaches to the wall of the uterus and to the umbilical cord. Oxygen-rich, nutritious blood travels from Mom to the fetus by the umbilical vein in the umbilical cord.  The umbilical vein delivers the blood to the liver and then much of it travels on to the right side of the heart. Here it mixes with blood of the fetus and is sent on through two special openings, bypassing the nonfunctioning lungs, into the left side of the heart for distribution to the entire body.  After completing the circuit, the blood that has delivered oxygen and nutrients to the fetus now flows via major vessels back to the umbilical cord where the two umbilical cord arteries carry it back to the placenta.

While the placenta allows oxygen and nutrients to pass through it, it also filters out many potentially harmful substances and infections. Near term, the placenta produces hormones that play a role in triggering labor and delivery.  After the baby is born, the placenta’s job is done and the placenta is delivered as the afterbirth.

In some cases the placenta may not develop correctly or function as well as it should. It may be too thin, too thick or have an extra lobe, or the membranes may be improperly attached.  Most of these issues are detected via ultrasound.  Signs of a problem include vaginal bleeding and/or continuous abdominal pain.  If you’re pregnant and have questions about your placenta, ask your doctor about it during an ultrasound.

Fifth disease and pregnancy

Thursday, June 4th, 2009

sick-child-21Fifth disease is a childhood illness that about half of us come down with when we’re kids, making us immune to it as adults.  It’s caused by parvovirus B19.  It got its odd name many years ago when it appeared fifth in a list of what were considered the common causes of childhood rash and fever.  Most often, it’s not a big deal in childhood, but it might be to a developing fetus if the mother contracts it during pregnancy.

Fifth disease  is a common, usually mild illness spread through the air from an infected person’s cough or sneeze. In children, it causes a distinctive “slapped cheek” rash and, less commonly, a low-grade fever, headache, sore throat and joint pain. Infected adults are less likely to develop a rash, but often experience joint pain and swelling, sometimes with mild flu-like symptoms. Symptoms generally appear between 4 and 14 days after exposure.

Fetal infection is rare. However, when a fetus does become infected, the virus can disrupt its ability to produce red blood cells, sometimes leading to a dangerous form of anemia and heart problems.  Serious consequences are more likely when a pregnant woman contracts the infection in the first 20 weeks of pregnancy.

To reduce the risk of infection, pregnant women should wash their hands thoroughly after touching tissues used by infected children and dispose of these tissues promptly. They also should avoid sharing drinking glasses or utensils with anyone who has or was exposed to the illness.

A pregnant woman who has been exposed to fifth disease should consult her provider promptly.  Blood tests can determine susceptibility or help diagnose the illness. If she is infected, her provider monitors the pregnancy carefully for signs of fetal problems.  There is no drug to treat the disease. The provider will most likely recommend repeated ultrasound examinations (weekly or every other week) for 8-12 weeks after the mother was infected. If ultrasound does not show any problems during this time, no further treatment is needed.

You can read questions and answers about this in the fact sheet written by the Organization of Teratology Information Specialists (OTIS).