How to determine pregnancy term by ultrasonography

How to determine pregnancy term by ultrasonography

It is unlikely there will be at least one woman who does not seek to define date of the forthcoming childbirth and presumable time of conception, having learned about the pregnancy. And it is important to doctor-obstetrician to know the exact term of pregnancy for assessment and monitoring of development and growth of a fruit and timely performing any given corrective therapy. Several ways to learn pregnancy term are known, but the most exact of them is ultrasonic scanning of a uterus and a fruit.


1. Remember that ultrasonography is safe for a fruit and has no restrictions at pregnancy. In case of the favorable course of pregnancy this type of perinatal diagnostics to you will be appointed three times.

2. Consider that on different terms of pregnancy the different volume of information on a fruit is available to the doctor, and the term of pregnancy is established by strictly certain criteria. Therefore so-called screening is developed and terms to which OUSE the research brings information, more exact, important for this period of time, are determined. For example, on gestational term 2-3 weeks in a cavity of a uterus are visualized only fetal egg, roughly speaking, the doctor can draw the conclusion there is pregnancy or not. About 4 weeks of a gestation the experienced ultrasonographer can see an embryo body (the size of fetal egg will average 3-4 mm during this period). On 4-5 week are registered heartbeat of the baby. Separate movements of the kid are visualized from 7th week of pre-natal life.

3. The head as independent anatomic education is defined from 8th week, and an extremity from 9th week of pregnancy. The doctor estimates the sizes of average internal diameter of fetal egg (SVD) and the kopchiko-parietal size of an embryo (KTR) at this period and compares the obtained data to tabular or the ultrasonography program of scanners and determines pregnancy term with a margin error ± 6 days. At the end of the first trimester of development (11-12 weeks) it is possible to scan separate structures of a brain of future child. At this particular time ultrasound specifies pregnancy term, the quantity of fruits is defined, measures thickness of vorotnikovy space and a nasal stone for an exception of chromosomal defects.

4. Know that further your kid on the ultrasonography display of the device will resemble real persons more and more. Every time during the research the doctor will take measurement of key indicators of biophysical development of a fruit, namely: bipariyetalny (between parietal hillocks) and lobnozatylochny the head sizes, a breast circle, a stomach circle, length of a nasal bone, femur length. Certain tables and the built-in programs for ultrasonography of devices by which it is possible to determine pregnancy term with an accuracy ± 1 week are developed.

Author: «MirrorInfo» Dream Team