الفهرس 
AnatomyOnly 14 pages are availabe for public view
 |  | from | 129 |  |  |
| | | from | 129 | | |
Abstract
The use of Doppler ultrasound is an integral part of the examination, and
should not be considered as a separate entity. The judicial use of Doppler is an
essential part of the diagnostic procedure and prognostic tool to study the
effectiveness of various management protocols in different high risk pregnancy
conditions. Doppler ultrasound investigation of the ductus venosus which is a fetal
vein connecting the umbilical vein with the IVC, has quickly become important in
monitoring fetuses with congestive cardiac diseases, chromosomal anomalies, and
intrauterine growth restriction. Doppler measurements of the ductus venosus have
also been used to identify fetuses at risk of hypoxia, acidemia and perinatal death.
The aim of this study was therefore to establish longitudinal reference ranges
for ductus venosus diameter, blood flow velocities and waveform indices during
the period between the 11th and 40th week of gestation. The study population of 230
women (690 observations). Maternal age ranges from 16- 45 years old and the
number of studied cases was at least 5 cases per week.
All pregnant women who met the following criteria were included in this
study: no risk pregnancy, accurate gestational age based on the last menstruation
date adapted with ultrasound parameters, gestational age between 11 and 40 weeks
, normal fetal growth ( between 10th and 90th percentiles of the growth chart),
normal amniotic fluid and normal Doppler pattern of MCA and UA arteries. Any
fetal and maternal complications were exclude.
Gestational age was confirmed by first trimester crown-rump length
measurement or assessment of head biometry (BPD and HC),
abdominal circumference (AC) and femur length (FL) at second and
third trimester.
In this current study the ductus venosus diameter, blood velocities and waveform
indices were determined over gestational age range of 11 - 40 weeks. Polynomial
regression lines for the 1st, 3rd, 5th, 10th, 90th , 95th, 98th and 99th percentiles were
calculated for the DV diameter, DV peak systolic velocity (S), maximum velocity
during atrial contraction (A), Systolic velocity/ maximum velocity during Atrial waveRatio (S/A Ratio), Pulsatility Index (PI), and Resistive Index (RI). Terms for
calculating conditional reference intervals were established.
Reference Ranges for DV diameter based on 690 observations showed
parabolic course which and ranged from 0.98 to 1.21 mm with average 1.09
mm at 1st trimester, and ranged from 0.98 to 1.60mm with average 1.24 mm
at 2nd trimester, and ranged from 1.34 to 2.09 mm with average 1.67 mm at
3rd trimester.
Reference Ranges for DV S wave velocity based on 690 observations showed
parabolic course which ranged from 11.17 to 69.66 cm/s with average 38.30 cm/s at
1st trimester, and ranged from 13.78 to 97.11 cm/s with average 51.40 at 2nd trimester,
and ranged from 27.77 to 94.27 cm/s with average 61.68 at 3rd trimester.
Reference Ranges for DV A wave velocity based on 690 observations shows
parabolic course which ranged from 1.61 to 25.29 cm/s with average 11.38 at 1st
trimester and ranged from 2.96 to 49.42 cm/s with average 21.10 at 2nd trimester,
and ranged from 9.65 to 56.57 cm/s with average 30.71 at 3rd trimester.
Reference Ranges for DV S/A ratio based on 690 observations showed parabolic
course which ranged from 2.47 to 5.94 with average 2.83 at 1st trimester and ranged
from 2.11 to 4.53 with average 2.94 at 2nd trimester, and ranged from 1.54 to 5.02
with average 2.55 at 3rdtrimester.
Reference Ranges for DV PI based on 690 observations showed parabolic course
which ranged from 0.84 to 1.39 with average 1.10 at 1st trimester, and ranged from
0.74 to 1.16 with average 0.88 at 2nd trimester, and ranged from 0.45 to 1.34 with
average 0.75 at 3rd trimester.
Reference Ranges for DV RI based on 690 observations showed parabolic course
which ranged from 0.62 to .85 with average 0.72 at 1st trimester, and ranged from
0.55 to 0.77 with average 0.54 at 2nd trimester, and ranged from 0.36 to 0.83 with
average 0.53 at 3rd trimestCONCLUSION
Our experience shows that Ductus venosus Doppler indices are raising great
concern in the follow up of the fetuses, especially those of high risk pregnancies,
suspected chromosomal or congenital anomalies, also our reference range may be
used as base line data for assessment of some fetal conditions associated with cardiac
function, especially when fetal growth restriction, anemia, hypoxia. Hence the need of
sitting normal range is of great importance. We tried to put a reference range based on
a centile module for our population.
We believe that Doppler velocimetry of DV has become an important tool for
fetal assessment, whose clinical use requires experienced professional with in-depth
knowledge and critical sense to explore its diagnostic potential. The reference ranges
obtained in this study were contribution to a better understanding of vascular
phenomena, permitting the diagnosis of both fetal well- being and deviation from it
using a noninvasive method that reflect the functional alterations of the fetal venous
system.
Our experience suggests that extreme caution must be taken in measuring DV
Doppler indices, at first the measuring is difficult especially when performed by
beginners but with training it becomes easier, also we have found that it becomes
increasingly difficult to establish Doppler frequency spectra from DV near term due
to a greater frequency of fetal breathing movements but at the early pregnancy
becomes less difficult.