Pregnancy (Due Date) Calculator

General Ultrasound Abdominal Ultrasound Upper abdominal scans encompass the liver, pancreas, kidneys, gallbladder, spleen and aorta. If your doctor has requested a scan of these structures, you will be required to fast. For adults, no food or liquid other than sips of water are permitted for 6 hours prior to the scheduled appointment time. Children are required to fast for 4 hours. An early morning appointment is recommended. Renal Ultrasound Renal ultrasound scans assess the kidneys, bladder and prostate in men. You will be required to fast for hours prior to your appointment. We recommend that you finish drinking 1 litre of water an hour prior to the exam.

Dating Scan

URL of this page: It is also used to check the female pelvic organs during pregnancy. Watch this video about: Ultrasound How the Test is Performed To have the procedure: You will lie on your back on an exam table. The person performing the test will spread a clear, water-based gel on your belly and pelvis area.

Midlands practice providing detailed obstetric scans to our pregnant patients and full radiology ultrasound service to the referring GP. Consultant Radiologist led service.

Practical Obstetrical Ultrasound, p Rockville, MD, Aspen, Averaging the gestational ages derived from two or more measurements has been shown to be more accurate than using any single parameter. Because of the greater accuracy of the early study, ultrasound examinations subsequent to an early study should not be used to revise the estimated date of confinement EDC , but rather should be used as a measure of the quality of fetal growth between the two studies.

Similarly, it is not appropriate to revise an EDC on the basis of an ultrasound examination if the patient’s menstrual dates are within the range of error of the ultrasound method. If significant discrepancy is seen between two ultrasonographically measured fetal dimensions more than a 2-week difference , then the ultrasonographer must consider the possibility of an error in measurement technique.

If a critical reevaluation reveals no error, then asymmetry in fetal growth may be present. Growth asymmetry may occur as a result of physiologic alteration in fetal head shape brachycephaly or dolichocephaly or in association with intrauterine growth restriction IUGR , macrosomia, or a fetal anomaly. The survey includes a confirmation of fetal number, viability, position, assessment of amniotic fluid volume, and location of the placenta.

In assessing fetal biometry, the applicable standard fetal measurements already discussed, including CRL, BPD, abdominal circumference, and femur length, should be taken. The estimation of fetal weight is a clinically useful parameter computed from the fetal biometric measurements.

Ultrasound pregnancy

The timing of certain tests, the monitoring of the baby’s growth, and the correct diagnosis of premature labor, or being truly “overdue,” postdates , as well as many other situations that arise in the course of a typical pregnancy, all depend on a correct determination of the EDC for appropriate management. In the past, the EDC was calculated by using Naegele’s Rule, which determined the date by subtracting 3 months from the 1st day of the last period and then adding 7 days. In fact, when a woman who has very regular, “textbook” 28 day cycles presents for prenatal care, this often turns out to be the correct EDC more often than not.

Other information used to calculate the gestational age, or the number of weeks and days from the first day of the last menstrual period LMP , includes the size of the uterus on pelvic bimanual examination.

Find out about itching during pregnancy, including causes, ways to ease itching, and when you need to seek medical attention fast for possible intrahepatic cholestasis of pregnancy (ICP), also called obstetric cholestasis.

In some cases of embryonic demise, the yolk sac is deflated or irregular. Fetal number, location, and presence and rate of heart rate should be clearly evaluated and documented. An attempt to determine chorionicity should start during the first-trimester ultrasound. Thick interfaces between gestational sacs suggest dichorionic pregnancies, and thin or absent membranes likely represent monochorionic twins.

A corpus luteum cyst may be observed in the maternal adnexa, usually 3 cm or less in diameter. Both adnexa should be evaluated for the presence of large ovarian cysts such as occurs in ovarian hyperstimulation syndrome , and solid masses such as in ovarian neoplasm. The uterus should also be evaluated for homogeneity, presence, and size and location of fibroids, especially intracavitary. Embryonic demise The first-trimester ultrasound presents an opportunity to identify some problematic pregnancies.


Generate a file for use with external citation management software. Create File Ultrasound Obstet Gynecol. New charts for ultrasound dating of pregnancy and assessment of fetal growth:

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Doppler Ultrasound The doppler shift principle has been used for a long time in fetal heart rate detectors. Further developments in doppler ultrasound technology in recent years have enabled a great expansion in its application in Obstetrics, particularly in the area of assessing and monitoring the well-being of the fetus, its progression in the face of intrauterine growth restriction, and the diagnosis of cardiac malformations.

Doppler ultrasound is presently most widely employed in the detection of fetal cardiac pulsations and pulsations in the various fetal blood vessels. The “Doptone” fetal pulse detector is a commonly used handheld device to detect fetal heartbeat using the same doppler principle. Blood flow characteristics in the fetal blood vessels can be assessed with Doppler ‘flow velocity waveforms’. Diminished flow, particularly in the diastolic phase of a pulse cycle is associated with compromise in the fetus.

Various ratios of the systolic to diastolic flow are used as a measure of this compromise. The blood vessels commonly interrogated include the umbilical artery , the aorta , the middle cerebral arteries , the uterine arcuate arteries , and the inferior vena cava. The use of color flow mapping can clearly depict the flow of blood in fetal blood vessels in a realtime scan, the direction of the flow being represented by different colors.

Color doppler is particularly indispensible in the diagnosis of fetal cardiac and blood vessel defects , and in the assessment of the hemodynamic responses to fetal hypoxia and anemia. A more recent development is the Power Doppler Doppler angiography. It uses amplitude information from doppler signals rather than flow velocity information to visualize slow flow in smaller blood vessels.

A color perfusion-like display of a particular organ such as the placenta overlapping on the 2-D image can be very nicely depicted. Doppler examinations can be performed abdominally and via the transvaginal route.

5 Fascinating Facts About Fetal Ultrasounds

Fetal ultrasound measurements can show how the baby is growing and detect abnormalities. During pregnancy many different ultrasounds measurements can be done. Gestational Sac GS The gestational sac GS is a structure that surrounds an embryo and is likely the first pregnancy structure that can be seen on ultrasound in early pregnancy. The GS encloses not only the embryo, but also the amniotic fluid, which helps to nourish and protect the developing baby. The gestational sac is the structure ultrasound technicians look for when they need to confirm the presence and viability of an early pregnancy.

It can be measured across and the weeks of the pregnancy can be determined with about 5-day accuracy.

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You may like to take a look at charts for crown-rump length , biparietal diameter , femur length , abdominal circumference , gestational sac diameter , yolk sac diameter and intrauterine fetal weight. If you have problems understanding and calculating your due date, check out and download a copy of the Ob calculator by York Winston. Hutchon’s site and the Gestation Network also provide pregnancy calculators.

A large number of mails I received are about fetal anomalies, I have therefore tried to put together a Catalogue of Web pages which describe in some detail specific congenital anomalies that are diagnosable by ultrasound. You can visit the page here. I am pregnant for 7 weeks. I went for a scan yesterday and was told I should have a full bladder. They made me drink 4 cups of water and my bladder was almost bursting at the end of the session.

Is this really necessary? A full bladder is usually necessary when the scan is done abdominally and in the early part of pregnancy. This would tend to lift the uterus up a little bit and being in front displaces the bowels away and act as an echo-lucent windows for the ultrasound to pass through. Ultrasound doesn’t go through air as in the bowels well but transmits perfectly through liquid as in the case of the urine in the bladder.

Obstetric ultrasonography

International conference on transition and cord clamping at birth April It is increasingly recognised that the circulatory changes involved in transition at birth cannot occur within a few seconds of birth. While the healthy fetal circulation and the healthy neonatal circulation are moderately well understood, the underlying triggers, the precise sequence and speed of the changes in the circulation are not. How can we interefere in something we do not understand?

Online Clinical Calculators. Last menstrual period: Conception Occurred: (about two weeks after last menstrual period).

This scan will also show if you are expecting a multiple pregnancy. What to Tell us? If you have recently experienced painful cramping or PV bleeding How to Prepare? Please drink 1 litre of water and hold for one hour prior to your appointment. Do not empty your bladder until after the examination. What does the procedure involve? The sonographer will tuck a piece of tissue into your underwear to protect your clothes, then drop some gel onto your abdomen.

This helps the scanning head to glide smoothly over your skin to get a clear image. Most dating scans are done with a trans-abdominal transducer and require a full bladder. However, if the pregnancy is in very early stages, the gestational sac and foetus may not be big enough to visualise and you may be offered an internal, transvaginal TV scan which will result in clearer images.

How long will it take? When my results be available? Your image films will be provided to you at the completion of appointment.

How to Identify Fetal Dating On 1st Trimester Using Ultrasound