Diagnosis And Confirmation Of Early Pregnancy Biology Essay

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A prenatal ultrasound test uses high-frequency sound waves, inaudible to the human ear, that are transmitted through the abdomen via a device called a transducer to look at the inside of the abdomen. With prenatal ultrasound, the echoes are recorded and transformed into video or photographic images of the baby. The healthcare provider uses a transducer to produce sound waves into the uterus. The sound waves bounce off bones and tissue returning back to the transducer to generate black and white images of the fetus.

Ultrasound scan is currently considered to be a safe, non-invasive, accurate and cost-effective investigation in the fetus. It has progressively become an indispensible obstetric tool and plays an important role in the care of every pregnant woman. The sensation many mothers and fathers feel when they first see live ultrasound images of their fetal babies brings a fascinating reality and a new dimension to the parental experience of pregnancy and childbirth. There are many uses for the ultrasound during pregnancy. Ultrasound can be used for diagnosis and confirmation of early pregnancy, determination of the gestational age, assessment of fetal size and diagnosis of fetal malformation. In addition to the uses of the ultrasound is for placental localization, multiple pregnancies and hydramnios and Oligohydramnios. There are many different types of ultrasound using in pregnancy, but the principle process is the same. These types include transvaginal scans, abdominal ultrasound, 3-D and 4-D ultrasound and doppler ultrasound. The ultrasound has become a standard procedure used during pregnancy.

After marriage each man and woman will think to have children. There is no other way to describe parenting than joyous. Throughout our life we experienced many happy occasions, but nothing that can compare to the moment we know that we are going to have a baby for the first time. During pregnancy both mother and father are interested to know more about their baby’s growth, development and wellbeing. All these health concerns can resolves by the pregnancy ultrasound. Ultrasound during pregnancy is a great method to obtain information about fetal development and wellbeing. In this essay I’m going to talk about the different uses of ultrasound during pregnancy and different types of ultrasound.

When ultrasounds are performed?

Ultrasounds may be performed at any point during pregnancy, and the results are seen immediately on a monitor during the procedure. The number of ultrasounds that should be performed during pregnancy is not recommended. Because ultrasound should only be used when medically indicated, many healthy pregnancies will not require ultrasound. The average number of ultrasounds varies with each healthcare provider. Additional ultrasounds might be ordered separately if a complication or problem related to the pregnancy is suspected. During this ultrasound, the doctor will confirm that the placenta is healthy and attached normally and that your baby is growing properly in the uterus. The baby's heartbeat and movement of its body, arms and legs can also be seen on the ultrasound.

Uses of Ultrasound:

As mentioned before that there are many uses for ultrasound during pregnancy and these uses are:

1- Diagnosis and confirmation of early pregnancy.

In the diagnosis and confirmation of early pregnancy the transvaginal ultrasound often provides better and earlier assessment. It allows the gestational sac to be identified at five weeks of gestation. With abdominal ultrasound , the gestational sac visible at six of gestation. Similarly, fetal heart activity can be detected with transvaqginal ultrasound at six weeks of gestation and at seven weeks of gestation with the abdominal ultrasound.

2- Determination of gestational age and assessment of fetal size

Ultrasound scanning has widely used for accurate assessment of gestational age. Useful when mother don’t know her last menstrual period, like in lactating amenorrhea .ultrasound also useful to assess the size of the fetus. Therefore, it is effective in differentiation between the fetus suffering from intra-uterine growth retardation (IUGR) and the one who is immature. A variety of measurement can be taken as early as 5 or 6 weeks after the mother's last menstrual period. Measuring the baby using ultrasound is most accurate in early pregnancy. It becomes less accurate later in pregnancy. The best period of gestation to verify the fetal age using ultrasound is between the 8th and 18th weeks of pregnancy. In addition, to determine gestational age accurately, use the first day of the woman's last menstrual period and confirming this gestational age with the measurement from an ultrasound exam. It should be remembered that in every case a series of measurement is more informative than a single one. ( V , Ruth Bennett., & L,Brown,1996).

Fetal body measurements reflect the gestational age of the fetus. These body measurements are:

A-Crown-rump Length (CRL)

This is the length of the embryo from the top of the head to the rump or end of the sacrum excluding the limbs .this measurement is used in the first trimester of pregnancy for estimation of gestational age.CRL is no longer accurate after twelve weeks due to the extension and flexion of active fetus. (Olds,s.,London,M.,& Ladewing,P,2000).

B-The Biparietal diameter (BPD)

This is the diameter between the two parietal eminences of the fetal skull. This measurement is used to assess the gestational age in the second trimester of pregnancy. Usually measured after thirteen weeks. It increases from about 2.4 cm at 13 weeks to about 9.5 cm at term. ( V , Ruth Bennett., & L,Brown,1996).

C- Head Circumference.

Measurement of head circumference is preferred in the third trimester of pregnancy. The BPD is accurate only if the head is the appropriate ovoid shape. Compression of the fetal skull occurs commonly in fetal malpresentation, such as breech, or in cases of oliohydramnios or multiple gestation .The head circumference is less affected by head compression and is therefore a valuable tool to assess gestational age. (Olds,s.,London,M.,& Ladewing,P,2000).

D-The Femur length (FL)

Although any long bone may be used to determine gestational age, the femur is easiest to image .This measures the longest bone in the body and reflects the longitudinal growth of the fetus. Its usefulness is similar to the BPD in determining the gestational age.

E-The Abdominal circumference (AC)

The single most important measurement to make in late pregnancy.It reflects more of fetal size and weight rather than age. If the estimated date of birth has been established with early ultrasound measurement, the abdominal circumference measurement may be sufficient to monitor fetal growth. It is useful to detect intra-uterine growth retardation (IUGR), macrosomia and iso-immunization (due to ascites). (Olds,s.,London,M.,& Ladewing,P,2000).

3- Diagnosis of fetal malformation

Many major and minor structural anomalies in the fetus can be diagnosed by an ultrasound scan. The scan usually performed before 20 weeks of gestation, though not with 100%accuracy. A basic ultrasound of fetal anatomy should include evaluation of the following:

Head shape and size to detect hydrocephaly , microcephaly or anencephaly. To evaluate the face for clefts and neck for presence of cystic hygroma.(figure 1)

Spine to detect meningomyelocele or spina bifeda.

Chest and heart to detect diaphragmatic hernia, pericardial teratoma,pleural effusion and congenital heart disease.

Abdomen to detect omphalocele, gastroschitis, tracheoesophagal fistula, dilated renal pelvic and polycystic kidney.

Extremities for skeletal dysplasia.

Figure 1

Cleft lip

4- Placental maturity and localization.

Throughout gestation the placenta undergoes maturational changes that may be visualized by ultrasound. The ultrasound has become very effective in the localization of the site of the placenta and determining its lower edges, thus making a diagnosis or an exclusion of placenta previa or abruptio placenta. In this case mother needs special care and need to deliver by caesarian section.

5- Multiple Pregnancies.

The ultrasound can determine the number of fetuses inside the uterus, specialy medication induced pregnancies such as Clomid induced pregnancy or IVF pregnancy. These medications mostly result in multiple pregnancies. (Figure 2)

Figure 2

Triplet at 8 weeks

of gestation

6- Hydramnios and Oligohydramnios.

The volume of amniotic fluid in the uterus serves as an important indicator of fetal well-being. Excessive (Hydramnios) or decreased (Oligohydramnios) amount of liquor (amniotic fluid) can be clearly depicted by ultrasound. Both of these conditions can have adverse effects on the fetus. In both these situations, careful ultrasound examination should be made to exclude intrauterine growth retardation and congenital malformation in the fetus such as intestinal atresia, hydrops fetalis or renal dysplasia. Olds,s.,London,M.,& Ladewing,P,2000).

Ultrasound scanning is of great value in other obstetric conditions such as confirmation of intrauterine death, verification of fetal presentation in uncertain cases, evaluating of fetal movements, tone and breathing as well as Diagnosis of uterine and pelvic abnormalities during pregnancy e.g. ovarian cyst.

Types of ultrasound

There are many types of ultrasound and each type that can be used during pregnancy, for various reasons. These types include:

1- Abdominal ultrasound.

An abdominal ultrasound is where the ultrasound probe is placed on the woman's abdomen to view her uterus and unborn baby. This is the most common method used, especially after 12 weeks of pregnancy (when the uterus has grown up and out of the woman's bony pelvis).

2-Transvaginal Scans

With specially designed probes, ultrasound scanning can be done with the probe inserted into the vagina of the patient. Once inserted, the probe is close to the structured being imaged and so provides better images and therefore more information. It can be used for patients who are obese and in the early stages of pregnancy. The better images are the result of the scan head’s closer proximity to the uterus and the higher frequency used in the transducer array resulting in higher resolving power. Fetal cardiac pulsation can be clearly observed as early as 6 weeks of gestation.

3- Doppler ultrasound.

Doppler ultrasounds are done in the same way as abdominal ultrasounds, but they study the fetal blood circulation (usually through a blood vessel), Thus used to look at blood flow between the uterus and placenta. This technology is very effective in assessing the function of the placenta and the well-being of the fetus as well as the progression in the face of intrauterine growth retardation. To add to the uses of Doppler ultrasound, is the diagnosis of cardiac malformations. Doppler ultrasounds tend to use higher intensities than diagnostic abdominal and vaginal ultrasounds and emit continuous sound waves (not pulsed).

4- 3-D and 4-D Ultrasound

3-D ultrasound is a 3 dimensional image of the fetus. The transducer takes a series of images, thin slices of the subject, and the computer processes these images and presents them as a 3 dimensional image. This can obtain views that might not be available using abdominal ultrasound .Furthermore, the measurements are more accurate by using this type of ultrasound and it is useful in detecting birth defects.4-D or dynamic 3-D scanners are very attractive for the population as they are able to look at the face and movements of their baby before birth magazines. This is thought to have an important catalytic effect for mothers to bond to their babies before birth.


In conclusion pregnancy ultrasound is a method of obtaining images of your baby, inside the uterus, by using high frequency sound waves. No x-rays or ionizing radiation is involved and there are no reported side effects for this procedure at the diagnostic power levels that our machines use. There are many different uses for ultrasound during pregnancy. Ultrasound can be used to determine if the baby is present and the gestational age of the baby as well as how many babies there are. It will also help in the diagnosis of any abnormality or problem. The ultrasound will evaluate the position of placenta in relation to birth canal. Pregnancy ultrasound can be performed at any stage during pregnancy by using different types of ultrasound. The types of ultrasound are transvaginal scan, abdominal ultrasound, Doppler ultrasound and 3D and 4D ultrasound. From this we can see the importance of ultrasound for mother and father to follow the growth and development of their baby and enjoy each moment of it.