Pregnancy is dated from the first day of the last menstrual period, so at four weeks, a woman is just due for a menstrual period.
At 4.5 to 5 weeks, a gestational sac may be seen in the uterus using transvaginal ultrasound, Joseph Woo, M.
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An early pregnancy ultrasound is medically indicated during the first trimester of the pregnancy for the following reasons: What types of ultrasound are there?
Although there is more than one type of ultrasound exam, the principle process in each procedure is the same.
These results are averages for when specific early pregnancy developmental milestones become detectable by transvaginal ultrasound.
Generally, an abdominal ultrasound is less sensitive and may not detect these milestones until a week or later in the pregnancy.
A common use of ultrasound in early pregnancy is to calculate a gestational age.
For this purpose, an ultrasound is considered a highly accurate means of determining gestational age.
In a normal pregnancy, the ultrasound results can offer an estimate of the gestational age to within five to seven days of accuracy.
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An ultrasound is a procedure that uses high frequency sound waves to scan the pelvic cavity and abdomen of a woman, and then creates a sonogram (a picture) of the placenta and the baby.