Preliminary dating and growth assessment
The Arctic is an area of high petroleum resource potential, low data density, high geologic uncertainty and sensitive environmental conditions.
A large portion of the remaining global endowment of oil and gas resources has long been thought to exist in the high northern latitudes of Russia, Norway, Greenland, United States, and Canada.
Fetal heart rate tends to vary with gestational age in the very early parts of pregnancy.
Normal heart rate at 6 weeks is around 90-110 beats per minute (bpm) and at 9 weeks is 140-170 bpm.
It has progressively become an indispensible obstetric tool and plays an important role in the care of every pregnant woman. The embryo can be observed and measured by about five and a half weeks. The viability of the fetus can be documented in the presence of vaginal bleeding in early pregnancy.
Ultrasound can also very importantly confirm the site of the pregnancy is within the cavity of the uterus. A visible heartbeat could be seen and detectable by pulsed doppler ultrasound by about 6 weeks and is usually clearly depictable by 7 weeks.
Movements such as fetal heart beat and malformations in the feus can be assessed and measurements can be made accurately on the images displayed on the screen.
There may be some discomfort from pressure on the full bladder.
Currently used equipments are known as real-time scanners, with which a continous picture of the moving fetus can be depicted on a monitor screen.
Very high frequency sound waves of between 3.5 to 7.0 megahertz (i.e.
The diagnosis of missed abortion is usually made by serial ultrasound scans demonstrating lack of gestational development.
For example, if ultrasound scan demonstrates a 7mm embryo but cannot demonstrable a clearcut heartbeat, a missed abortion may be diagnosed.