What Is An Ultrasound?

An ultrasound is a non-invasive medical procedure to help the doctors diagnose and treat medical conditions. It involves production of specific images of the structures inside your body that need to be examined with the help of high frequency sound waves. The image hence produced is called a sonogram, sonography or sonogram imaging.

Although sonograms mostly find their use in diagnosis of disease states, it is not limited to only that. They can be used for screening as well as monitoring therapy in various cases. Sonograms offer a brilliant opportunity to have a look into your internal organs and detect any abnormal or significant changes in them. You are likely to be told by your physician to get a sonogram in a large number of instances – from bowel problems to bladder issues to even pregnancy.

How can you get an ultrasound done?

The procedure is quite simple. You are instructed to lie down and expose the part of the body that is to be scanned. A sticky gel is then rubbed onto that area and a device called a transducer is rubbed over the gel. The transducer emits high frequency sound waves which are directed through the layers of the skin towards the organ under examination. These waves create echoes that bounce off from the structures inside your body and get recorded by technicians. These echoes have their own frequencies which can be measured and converted into an image with the help of a computer.

It has been known for ages that solids and fluids reflect exhoes of different frequencies. Ultrasound technology makes use of this fact, which is why they are most sensitive at these solid-fluid interfaces. It is, therefore, logical that you are almost always sent for sonograms in order to confirm pregnancy. There is no better technology to view your unborn fetus and record its movements in real time.

The process can last from 5 minutes to even half an hour, depending upon the areas that need to be scanned. A bit of discomfort temporarily is a normal feeling for first-timers when your physician presses the transducer hard for better visuals, but there is nothing to worry about, since the entire procedure is non-invasive.

What the different kinds of ultrasounds?

All kinds of ultrasounds are based on the same principle. But there remain some basic differences that allow us to classify ultrasounds into six major categories: Doppler Imaging, Obstetric Ultrasound, 3D and 4D Ultrasound, Carotid Ultrasound, and Echocardiogram. The distinction mostly lies in the way images are produced and the fundamental working of the equipments.

The 3D and 4D ultrasounds are especially fascinating. In contrast to conventional ultrasounds that produce flat images, 3D sonograms get the images formatted in three-dimensional form by the computer, thus allowing for better understanding and diagnosis. A detailed description of 3D ultrasounds has been provided below.

What is 3D ultrasound?

Three dimensional ultrasound, or 3D ultrasound as it is popularly known as, is an advanced ultrasound technique that produces three dimensional image of the structure being examined. It finds usage commonly in gynecology and obstetrics where it produces 3D images of the fetus growing inside the mother’s womb.

Three dimensional ultrasound technique is fundamentally a bit different from the regular two dimensional technique that is more widely used. While 2D scanning involves sending sound waves straight down through the skin so that they get reflected back from the viscera in the body, in 3D ultrasound, the waves are sent at different angles. The echoes getting reflected back are read and processed by a sophisticated computer program. A three dimensional volume image of the structure under examination is reconstructed with the help of the program.

Another variant, called 4D ultrasound, is essentially similar to 3D ultrasound, but differs in the fact that the former also uses time as a dimension. Basically, 4D ultrasound provides a real time three dimensional scanning of the structure.

Where is 3D ultrasound used?

Being a sophisticated procedure, 3D ultrasounds are not used routinely in examination of structures inside the body. They find their clinical use mostly in the obstetrics department in order to scan for fetal anomalies. You doctor is unlikely to send you for a 3D ultrasound unless there arises a medical need for the same.

When can you go for a 3D ultrasound?

The thumb rule is that a pregnant mother should get at least two sonograms done during her pregnancy. It can be done anytime during the first trimester (three months) of pregnancy in order to confirm or date it and determine the number of fetuses. If the mother wishes to listen to the fetus’s heartbeat during the ultrasound, she is advised to get it done only after 6 weeks have elapsed. In most cases, the fetus’s heart is formed by this time.

A level 2 ultrasound which involves a full anatomy scan is performed by a trained sonographer with sophisticated equipments between week 18 and week 22. High risk pregnancies or women carrying multiple fetuses are frequently told to get scans for constant monitoring. They are also advised to undergo several other tests to monitor progress and detect any complication as early as possible.

According to medical textbooks, sex of the fetus can be detected as early as the 12th week of pregnancy since the genitalia usually develops by that time. In reality, though, few medical centers and hospitals carry out the procedure before the 20th week. Therefore, women impatient about the subject of their fetus’ sex has to visit 3D ultrasound centers in order to find out whether it is going to be a boy or a girl.

Some ultrasound centers, quite understandably, take advantage of this fact and claim to confirm the sex of the unborn child as early as 15 weeks of gestation. In most cases, it is either inaccurate or simply impossible, and the woman has to return again when the fetus is more mature. Thus, she has to pay twice for determining the sex of her fetus.

At 15 weeks, the success rate of finding the sex with accuracy is only 50% which shoots up to 99% by the next week. Most private ultrasound centers offer scans 16th week onward – a good 4 weeks in advance when compared to the services offered at hospitals.

However, 3D ultrasounds offer best results in the 24-32 weeks period (ideally between week 26 and week 30). After 32 weeks, the fetus descends into the pelvis and getting good 3D images of the fetus is only possible with the help of an experienced and expert ultrasound technician. Several factors determine whether clear images will be possible towards the end of pregnancy. These are position of the baby inside the womb, the placenta, and the amount of amniotic fluid present around the face.

How safe is it?

Ultrasounds are a form of energy that has been shown to cause effects in human tissues even at low doses. According to the Food and Drug Administration (FDA), laboratory studies have proved that ultrasounds may cause physical effects in the body like mechanical vibrations and a slight rise in temperature. This finding, however, has not been proved to be associated with definite injury at cellular level.

Since 3D ultrasounds are mostly used for obstetrical purposes, the FDA has set up an upper limit for obstetrical ultrasound at 94 mW/sq cm. This ultrasound energy limit holds for all types of ultrasounds regardless of whether they are 2D, 3D or 4D.

Technically speaking, getting a 3D or 4D sonogram is as safe as a 2D one. However, the fact that you are having a 3D ultrasound only for a souvenir photo or recording usually implies that you are exposing yourself and the unborn life inside you to more ultrasound energy for a longer period of time than medically necessary. Despite there being no scientific proof regarding this, exposure to high frequency waves over recommended safety limits may do some silent harm that we don’t know yet.

It is important to note here that no conclusive evidence that 3D ultrasounds may have harmful effects on the health of the mother or that of the baby has been established yet. The American Institute of Ultrasound in Medicine (AIUM) however, recommends that 3D ultrasounds should be used knowing that some risk, although not established yet, may exist.

What are keepsake ultrasounds and what are the risks associated with them?

3D ultrasound technology possesses the potential of being used for examination of any part of the body, but elective 3D ultrasounds are conventionally used only in the obstetrics department. These are performed on pregnant women with the sole motive of the mother willing to see her unborn fetus, what it looks like or whether it is a male or female. These elective 3D ultrasounds are commonly referred to as keepsake ultrasounds in medical literature.

The main idea of keepsake ultrasounds is that these are performed without any medical requirement. Since no medical benefit is obtained, the exposure is looked down upon by the FDA as unnecessary and potentially dangerous. There is no way to regulate the time of each imaging session because keepsake ultrasounds are carried on only on the mother’s will. Further, there is no control over how many such unapproved sessions will be occurring during the period of pregnancy.

It is widely believed by scientists that when ultrasound enters into the bodies, it heats up the tissues slightly. It may also produce areas of partial vacuums or air filled cavitations inside the tissues and body fluids. These usually do not pose a threat to the body because they are used only for a short period of time, and only when a medical need arises.

Since keepsake 3D ultrasounds are unregulated and off the book at times, the mother and the unborn fetus remain susceptible to harm under the effect of these sound waves. There may be cases where the ultrasound machine is used for imaging for as long as an hour if the mother wants to get a video of the fetus. Such procedures not only put the health of both of them under threat, but also fall under abuse of scientific equipment.

Effects of these ultrasounds

An increased incidence of speech delays and left-handedness was observed in boys who had undergone unregulated ultrasound imaging in utero. When not hereditary in nature, increased left-handedness is a marker for brain problems. Early studies, thus, showed that some link, however small, may exist between ultrasounds and subtle neurological damage in kids.

In August 2006, Pasko Rakic, chair of Department of Neurology, Yale School of Medicine, announced the results of a study where pregnant mice were subjected to varying durations of ultrasound. On examination of the brains of the offsprings, it was found that they showed damage consistent with that found in the brains of autistic people. The research also proved a possible connection of ultrasound technology with neurodevelopmental issues like dyslexia, epilepsy, mental retardation and schizophrenia in children. Moreover, the results showed that damage to brain cells was directly proportional to the time of exposure, meaning longer exposures led to more damage.

3D ultrasounds are not recommended before 17 weeks of gestation. Seeing the picture of a growing fetus less than 17 weeks may be too early for a few women. The mother may get a feeling that the fetus is alien or that the baby is ‘not really a baby yet’. This may ultimately have a negative effect on mother-fetus bonding, thereby resulting in unintentional harm.

Finding of false positives or harmless cysts that would have remained undetected if not for 3D ultrasound may cause anxiety and distress to the mother. This is another example of unintentional harm done by ultrasounds, especially when performed by inexperienced ultrasonographers.

How else can you detect pregnancy?

Missed period is usually the earliest sign of pregnancy in most women. People begin to suspect pregnancy when they stop bleeding for a month or two after a sexual experience. Implantation bleeding, commonly referred to as spotting, may often be misleading in this regard. The fact that mild cramps are known to accompany spotting makes it difficult to distinguish from normal menstruation.

It must be remembered that spotting only occurs when you are pregnant. In case you are experiencing small amounts of brownish blood for a few hours or even a couple of days, it probably means you are somewhere in the first trimester of pregnancy.

If your urge to use the washroom has increased in the last few days, the possibility of you being pregnant is something that must be considered with seriousness. Your pregnancy may lead you to sense an increased pressure in your urinary bladder as early as 5 to 6 weeks of pregnancy. The symptoms are, theoretically, thought to lessen as the pregnancy progresses through the second trimester.

It is reasonable to wonder why your bladder gets under pressure when your uterus is the one holding your baby. The answer to this lies in the physiology of the human body. It is a known fact that there is almost 50% increase in the mother’s blood volume during pregnancy in order to support and nourish the growing fetus with optimum nutrients. As a result, more blood gets filtered through the kidneys of the mother leading to more urine.

Anatomically, the uterus lies just behind the urinary bladder. With progress in pregnancy, the uterus grows in size and pushes the bladder in front of it and the rectum behind it. This results in an increased urge to urinate as well as to defecate. As the second trimester approaches, the uterus grows upwards into the abdomen.

Many mothers encounter changes in the breast during week 8 to week 12. All the time that you remain pregnant, your body’s hormones, especially estrogen and progesterone, run riot. This leads to some notable changes in and around the breasts.

Breast changes are more prominent in mothers pregnant for the first time. There is observable increase in size of the breasts as the tissues start preparing themselves for milk production for proper nursing of the future baby. The nerve endings become more sensitive at this stage, resulting in tenderness around that region.

Your obstetrician is likely to rely on a more prominent change in the breast following pregnancy like the darkening of areola. Areola is the dark pigmented area surrounding your nipples. In the first trimester (that is, the initial 3 months of pregnancy) areola becomes more prominent and darker, thus serving as an important clinical finding for diagnosis of pregnancy.

What are the early symptoms experienced by a pregnant woman?

Morning sickness is a fairly popular term during the period of pregnancy. It refers to the feeling of nausea and vomiting experienced frequently by the mother in the early weeks of pregnancy. This is more prevalent between week 4 and week 16.

Apart from hormones, stress and fatigue play an important role in determining whether you will experience these symptoms or not. The fact that women who are pregnant for the first time have been observed to be more susceptible to developing morning sickness validates the idea that both physiological as well as emotional factors are involved.

Genetics and sensitivity of the brain’s command center undoubtedly mediate nausea and vomiting, but anxiety plays its part too. First-timers are often unsure about how to get through the nine months, and are less prepared emotionally and physically for the onslaught of hormones. Emotional stress has been known to trigger gastrointestinal upsets, and it is hardly surprising that nausea and vomiting are found more frequently in emotionally fragile moms-to-be than in those who are not as nervous.

Most cases of morning sickness do not require any kind of medical intervention. Home remedies like ginger or tea can help nausea, but severe vomiting may require additional medical management. Drugs like Diclegis (pyridoxine and doxylamine) can be used to treat such symptoms.

In severe cases of morning sickness, dehydration may be an important feature because of excessive vomiting throughout the day. When this happens, the woman is needed to be hospitalized immediately and given plenty of fluids followed by treatment in accordance to her symptoms.

Sudden feeling of exhaustion, day in, day out may also point towards pregnancy. Raised levels of progesterone are believed to increase drowsiness. This, coupled with whole day of nausea and frequent urination, aggravates your exhaustion. Lack of appetite can also be a reason of fatigue in the later months of pregnancy.

Cravings are an important part of every pregnancy. It is completely normal, during this time, to feel a sudden craving for foods that you previously used to dislike, or to feel an avulsion towards your favorite desserts. The possibility that ncreased yearning for certain foods may ruin your diet can be corrected if you know how to keep a tab on your food habits. Increasing the frequency of having food, but decreasing the amount in each go will help you maintain a balanced nutrition.

Other signs of pregnancy include a high basal body temperature and frequent mood swings. The only way to accurately know whether you are pregnant or not, is by undergoing a pregnancy test at home and duly following it up with a sonogram.

What tests can you perform to detect pregnancy?

The laboratory tests to detect pregnancy involve testing of blood for a hormone called, Human Chorionic Gonadotropin (hCG). This is the same hormone that you try to detect in a urine test conducted at home with the help of your pregnancy kit. In both the cases, presence of hCG confirms pregnancy.

A pregnancy test conducted at home is usually the best way to know whether you are pregnant or not. There are chances of getting a false positive or false negative result depending on when and how you conduct it, but if done right, the accuracy can rise to as high as almost 97.4%.

The workings of urine pregnancy tests are intricately associated with the hCG in your urine. This hormone is not normally found in your blood or urine. It appears in your urine only after the fertilised egg has been implanted into the uterine wall. The levels of hCG rises steadily from that point, doubling or tripling every three days or so.

So it is very important that you wait until the day you expect your periods to begin in order to take the test. Pregnancy tests can detect pregnancy even 5 days before your first missed period, but the sensitivity of the test is low then, which makes it prone to raise false alarms.

How to perform the test?

There are a variety of tests available to detect pregnancy, and each differs from the other in one way or another. Most pregnancy test kits come with instruction manuals. Going through the manual is extremely important because if not conducted properly, your pregnancy test will definitely mislead you. Even if you have performed a pregnancy test at home in the past, you need to read and completely understand the instruction manual of your new kit again since it may have different requirements.

Most pregnancy tests are uncomplicated and easy to perform. The kits include a stick that contains an area to place your urine and a single or double window to show the result. You simply need to place the stick in your urine stream so as to catch the midstream urine. The results can be obtained within minutes.

What about reading the result of the test?

There is rarely any ambiguity when it comes to reading the test, and results can be interpreted as either positive or negative. The test kit contains two windows, of which one is called the test window. This is typically the second window in line. It begins to show a line immediately after using the kit, implying that the test is in working condition.

The first window reveals the status of your pregnacy. It is essential to wait until the allotted time is over before reading the test. Reading it too soon may result in incorrect inference.

A single line or two lines in the form of a plus sign appearing in the first window indicates you are pregnant. Absence of any line implies you are not. Even if the line is faint, it means you are pregnant.

Occasionally, there may be only one test window present in some kits. In this case, both the test line and the result line appear in the same window. So in order to be pregnant, you must have two lines – one test and one result line – next to each other. If you have a single line, it indicates your pregnancy test is negative. Often, it is easy to misread the pregnancy indicator line because of the faintness. So you need to be careful before you discard the test as a negative one.

What about digital pregnancy tests?

A digital pregnancy test is much easier to read and is popular because it has nothing to do with line patterns. You no longer need to worry about the faintness of the pregnancy indicator and be nervous about reading it incorrectly.

The test is more user-friendly because the result is plainly displayed as ‘Pregnant’ or ‘Not Pregnant’ in the result window. Hence it is clear, unambiguous and indisputable. It is this advantage of the digital pregnancy test that has made it so popular.

An hourglass shaped figure appears in the results window as you wait for the result. It serves as an indicator for the proper functioning of the kit. So if you don’t see the hourglass, it is probably time to discard it and get a new test.

Although the accuracy of home pregnancy tests is pretty high, it is important to confirm pregnancy with other tests like ultrasound and radioimmunoassay as well. Since the time frame for physiological changes differs from one individual to another, a repeat test is always advisable.

How early can pregnancy be detected with the help of these tests?

Pregnancy can be detected as early as 5 days before your first missed period. This is around a week or so after fertilization of your egg. Taking a urine test around this time may give a positive result if you are pregnant.

Transvaginal ultrasonography can confirm pregnancy as early as the 5th week. Sonogram also lets you detect heart sounds of your fetus towards the end of the second month of pregnancy.

How accurately can pregnancy be detected before a missed period?

Presence of hCG in urine or blood can be established as early as 5 days before a missed period by a process named ELISA. So if you are in a hurry, you can always rely on that test to detect pregnancy from a sample of blood. It is the most advanced method used nowadays and possesses the ability to confirm your suspicions even before the initial symptoms begin to show.

That said, pregnancy tests are generally conducted after the first missed period, so as to minimize the chances of a false negative result. The principal of confirming pregnancy lies in detection of the hormone hCG, and adequate amount of it is required to be present in urine or blood for the test to detect it.

However, false positive and false negative results are not unheard of. The former can be obtained in conditions like choriocarcinoma, ectopic pregnancy, and hydatidiform mole where this hCG hormone is produced abundantly. False negative results can occur if the tests are not done properly. A repeat test after a few days usually helps in settling that issue.

It must not be forgotten that the estimated age of pregnancy at which different tests are said to be accurate is likely to vary from one woman to another, and hence, there is no fool-proof answer to how soon you can detect your pregnancy.