Dating of pregnancy

27 Jan

A positive pregnancy test 3 weeks previously for example, would indicate a gestational age of at least 7 weeks.Such information would be useful against the interpretation of the scans. In the presence of first trimester bleeding, ultrasonography is also indispensible in the early diagnosis of ectopic pregnancies and molar pregnancies. Determination of gestational age and assessment of fetal size.3.5 to 7 million cycles per second) are generally used for this purpose.

The timing of a positive pregnancy test may also be helpful in this regard to assess the possible dates of conception.

c) The Femur length (FL) Measures the longest bone in the body and reflects the longitudinal growth of the fetus. It increases from about 1.5 cm at 14 weeks to about 7.8 cm at term.

(Chart and further comments) Similar to the BPD, dating using the FL should be done as early as is feasible.

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.