الفهرس 
General ConsiderationsOnly 14 pages are availabe for public view
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Abstract
No single ultrasound measurement of the different anatomical features in the first trimester has been shown to have a high predictive value for determining early pregnancy outcome.
Several sonographic parameters are used to detect normal pregnancy outcomes in the first trimester. These include the size and location of the gestational sac, the growth rate of the gestational sac, the gestational sac size in relation to the presence or absence of a fetal pole and yolk sac, the size and shape of the yolk sac, the fetal heart rate, and the relationship between the mean size of the gestational sac and the CRL.
These multiple parameters have been devised to help identify an abnormal gestational sac or embryo. However, a review of the literature continues to reveal conflicting data on absolute parameters that can be reliably used to diagnose abnormal gestation at a single examination.
It is well known that every organ in the body or its function has a normal range of size or function.
Reviewing the literature does not reveal ultrasound measurement of the normal or abnormal range between YSD and GSD in uneventable first trimesteric pregnancy during the six week from LMP to predict its outcome.
The present study is novel in setting the normal range between YSD and GSD in uneventable pregnancy during the six week from LMP by two-dimensional vaginal ultrasonography.
This range is not only deduced from the cases of the present study but also
from cases of other reports (Lindsay et al, 1992; CHO et al, 2006) totaling
/ Summary and Conclusion Chapter 6
482 cases. These reports mentioned only the size of GS and its corresponding YS size but did not calculate the ratio between them.
The lonely study, which studied this relation, was that of Babinszki et al in 2001 but in 3-dimension scan by comparing YSV/GSV.
In doing so, in the present study, YSD and GSD alone then in combination are studied and statistically testified.
According to the result of the present study, the YSD alone is not of predictive value as regard the outcome as all cases of the abnormal outcome with measurable YS lie within the values of the YSD of the normal outcome group or within ± 2 SDs of its mean value.
In addition, the GSD alone is not of predictive value as regard the outcome in the first trimesteric pregnancy except in very few cases which show very small GSD with no growth in the follow up ultrasound.
To be of predictive value as regard the outcome in early pregnancy, the GSD must be related to discriminatory level at which the YS must be visible. In the present study, the discriminatory level of GSD is 10mm.
The proportion of GSD/YSD or YSD/GSD as regard the outcome in early pregnancy, before or after the embryonic pole appears, have high predictive value.
The range of normal outcome as regard GSD/YSD is 2.2 to 5 (p > 0.05) and as regard YSD/GSD is 0.45 to 0.20 (p > 0.05). This normal range has positive predictive value of 96.1% and negative predictive value of 96.1%, with sensitivity of 96.1% and specificity of 96.1%.
The abnormal outcome group with measurable YS, which shows disproportion of GSD/YSD or YSD/GSD, has positive predictive value of 100 % with sensitivity of 100 and specificity of 100%.
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Spontaneous regression of the yolk sac may occur more frequently but may not be noticed owing to the timing of imaging in most cases of spontaneous abortion.
The YSD / GSD of the abnormal outcome group with measurable YS is below lower limit of the normal range. This means that the YSD is proportionally small to GSD or by another meaning; the GSD is proportionally large to YSD.
The relation between YSD and GSD of the normal outcome group is statistically significant r = 0.712 (P > 0.01). This means a good direct linear relation between GSD and YSD in normal cases.
While, the relation between YSD and GSD of the abnormal outcome group with measurable YS is statistically of bad relation r = 0.168 (P > 0.01).This means that the relation is distorted between GSD and YSD in this group.
In addition, the relation between YSD and GSD of all cases of the study is statistically weak r = 0.334 (P> 0.01). This is a factual result as all cases of the study contain the normal and the abnormal outcome groups.
We can conclude a dictum for the range of proportion of YSD to GSD during the six week of gestation in normal pregnancy, which is the following:
The YSD is one third of GSD in most cases
The YSD is one fifth of GSD in some cases
The YSD is just below the half of GSD in some other cases.
This can be digitally represented as following:
0.45 some cases: upper limit
↕
YSD ≈ 0.33 of GSD in most cases
↕
0.20 some cases: lower limi