I
The National Ribat University.
College of Graduate Studies
and Scientific Research.
Study of the Placental Location in the Third
Trimester Using Ultrasound.
A Thesis Submitted in Partial Fulfilment of the
Requirements for the Degree of the M.Sc. in Medical
Diagnostic Ultrasound.
By
Khadra Abdulkadir Khalif
Supervisor:-
Dr. Elsir Ali Saeed
PhD in Medical Diagnostic Ultrasound
ھـ م - 1439 2018
I
Dedication
To my father, my mother, sisters, brothers, family and friends,
with love, respect, gratitude and appreciation.
I I
Acknowledgement
I would like to express my deep gratitude, indebtedness, respect
and profound thanks to my supervisor, Dr. Elsir Ali Saeed for
his support, invaluable comments, suggestions, keen
supervision, and constant encouragement, without which this
study could have not been in this form.
My special thanks due to Dr. Mohamed Elfa dil Mohamed
GarElnabi, for his appreciate orientation and valuable
guidance, who devoted a great deal of his precio us time
reading this dissertation.
My sincere thanks are also due to the administration and the
staff of Omdurman Maternal Hospital (Dayat Hospital), who
assisted me in obtaining the collection of this data. My special
thanks are due to my family who supported me morally and
materially throughout this study.
I am greatly indebted to the administration and the staff of
Afro-Asian Medical Training centre for their help during this
research.
I share any credit that might be accorded to this work with all
those who contributed to it. However, any shortcomings are
expressly mine.
I I I
Table of contents Title Page
Dedication ………………………………………………………... I
Acknowledgement ………………………………………………... II
Table of contents………………………………………………….. III
English Abstract…………………………………………………... V
Arabic Abstract …………………………………………………... VI
List of Figures……………………………………………………. VII
List of Tables …………………………………………………….. VIII
List of Abbreviations……………………………………………… IX
Chapter one………………………………………………………. 1
1.1.Introduction ………………………………………………......... 2
1.2. Statement of the Research Problem ……………………………. 3
1.3 .Objectives ………………………………………………… ….. 4
1.4.Organisation of the Research ………………………………….. 4
Chapter Two………………………………………………….. …... 5
Background and Literature Review………………………………… 6
2.1. placenta anatomy…………………………………………… 6
2.1.1. Development……………………………………………… 6
2.1.2. Structure…………………………………………………….. 8
2.1.3.Umbilical cord……………………………………… ……….. 9
2.1.4.Cord Insertion………………………………………… …… 9
2.2.1.5.Placental circulation……………………………………… 10
2.2. Physiology…………………………………………………… 13
2-3. Ultrasound Evaluation of placenta..................................... 14
2.3.1. Location…………………………………………………… 14
2..3.2 . placenta Echo Texture.................................................. 15
2.3-4. Retroplacental Uterine Wall................................................ 16
2-4.NormalVariants…………………………………………....... 17
2.5. Pathology of placenta………………………………………… 20
2.5.1.Placental infarction…………………………………............. 20
2.5.2 .Placental Causes of Antepartum Hemorrhage…….. ……… 20
2.5.3. Placental Abruption………………………………………. 20
IV
2.5.4. Placenta Previa…………………………………………….. 22
2.5.5. Vasa Previa…………………………………....................... 24
2.5.6. Placental Hematoma………………………………... …….. 25
2.5.7. Morbidly adherent placenta................................................ 26
2.5.8.Placental Tumours………………………………….............. 28
2.6. Previous studies……………………………………………… 28
Chapter Three……………………………………………………… 31
Methodology……………………………………………………... 32
3-1: Design of the Study…………………………………………... 32
3.2.Population of the Study………………………………………. 33
3.3.Data Collection…………………………………………………
32
3.4.Techniques utilized………………………….............................
33
3.5.Data Analysis………………………………. ………………
33
3.6.Ethical Approval……………………………. ……………….
33
4.Chapter Four.............................................................................
34
4.1.Results.....................................................................................
35
5.Chapter Five..............................................................................
44
5.1.Discussion...............................................................................
45
5.2.Conclusion...............................................................................
48
5-3.Recommendations...................................................................
49
References…………………………………………………………..
50
Appendices.................................................................................... 52
V
Abstract
Ultrasound is the best means to determine the location of
placenta and its proximity to the cervix. This descriptive
research is intended to assess the placental position in some
normal pregnant women in third trimester . This study was
conducted in Omdurman Maternal Hospital (known as Dayat
Hospital), from October to December 2017.
100 pregnant women in the Third Trimester were scanned by
ultrasound machine Toshiba-Power Vision-6000. The variables
used to set up this study were:-Mother Age, Mode of Delivery,
Hypertension, Diabetes, Number of Pregnancies, Fetal
Presentation, Gestational Age, Estimated Fetal Weight,
Amniotic Fluid Volumes and the Gravidity. Out of 100 pregnant
women, 56% were anterior, 42% were posterior and only 2%
were fundal. The ages between 25- 29 were the most frequencies
of pregnant women in the study. It is found that the pregnant
women who have hypertension were only 7% of the sample.
However, diabetes was only 6%. It is obse rved that only 2% of
pregnant women can have twins. Cephalic constitutes 92% o f the
sample, whereas breech comprises only 8%. According to the
estimated fetal weight, the most frequent weight was 3.1-3.5kg.
In short, it was observed that there is no correlation, between
the variables above mentioned and the placental location.
VI
خلاصة
يهدف هذا الموجات فوق الصوتية هي أفضل وسيلة لتحديد موقع المشيمة وقربها من عنق الرحم.
الحوامل العادية. أجريت هذه الدراسة النساءالمشيمة في بعض وضعلتصميم وتقييم وصفيالبحث ال
.2017في مستشفى أم درمان للولادة )المعروف باسم مستشفى الدايات(، من أكتوبر إلى ديسمبر
-الموجات فوق الصوتية توشيبا جهازالحوامل في الثلث الاخير من قبل النساء من مائة عددتم مسح
6000.
عمر الأم، طريقة الولادة، ارتفاع ضغط -:من كل المتغيرات المستخدمة لإعداد هذه الدراسة كانت
الدم، مرض السكري، عدد الحمل، عرض الجنين، عمر الحمل، وزن الجنين المقدر، كميات السائل
منهن ٪56الحوامل، كان النساءمن 100. ومن بين الحمل مرات عددالذي يحيط بالجنين و
النساء من 29و 25قاعي. وكانت الأعمار بين فقط منهن ٪ 2، و الخلفيمنهن ٪ 24، و الأمامي
ئي٪ من العينة. وتبين أن النساء الحوامل 37الحوامل في الدراسة، تشكل يعانون من ارتفاع اللا
من٪ فقط 2٪. ويلحظ أن 6٪ فقط من العينة. ومع ذلك، كان مرض السكري فقط 7ضغط الدم كانت
٪ من العينة، في حين 92نسبة رأسيال الجنين وضعتحملن التوائم. ويشكل الأمهات الحوامل كانتا
، الذي 3.5kg-3.1وفقا للوزن المقدر للجنين، كان الأكثر الوزن شيوعا .٪ فقط8 تشكلأن المؤخرة
.٪ من العينة32يشكل
وباختصار، لوحظ أنه لا يوجد ارتباط، بين المتغيرات المذكورة أعله وموقع المشيمة.
VII
List of Figures
Title Page
Figure 2.1 development of the placenta during the first 21 days of gestation 7
Figure 2.2 Normal Cord Insertion Sonogram of the uterus ………………… 10
Figure 2.3 Fetal and maternal circulation …………………………………... 12
Figure 2.4 Normal Early Placenta …………………………………………. 15
Figure 2.5 Normal Anterior Placenta ……………………………………… 16
Figure 2.6 Retroplacental Complex ……………………………………….. 17
Figure 2.7 Bilobed placenta. ………………………………………………. 18
Figure 2.8 Succenturiate placenta. ………………………………………… 18
Figure 2.9 Circumvallate placenta…………………………………………. 19
Figure 2.10 placenta membranacea. ………………………………………… 19
Figure 2.11 placental abruption……………………………………………… 21
Figure 2.12 placenta previa …………………………………………………. 23
Figure 2.13 vasa previa……………………………………………………… 25
Figure 2.14 subchorionic hematoma………………………………………… 26
Figure 2.15 Morbidly adherent placenta…………………………………….. 27
figure 4.1 Age and Placenta Location……………………………………… 35
figure 4.2 the Gravidity and Placenta Location………………………….. 36
figure 4.3 Mode of Delivery and Placenta Location………………………. 37
figure 4.4 Gestational Hypertension and Placenta Location……………… 38
figure 4.5 Gestational Diabets and Placenta Location ……………………. 39
figure 4.6 Number of Pregnancies and Placenta Location ………………… 40
figure 4.7 Fetal Presentation and the Placenta Location …………………. 41
figure 4.8 Estimated Fetal Weight and the Placenta Location…................... 42
figure 4.9 Amniotic Fluid Volume and the Placenta Location……………… 43
VIII
List of Tables
Title Page
figure 4.1 Age and the Placent Location……………………………………. 35
figure 4-2 The Gravidity and Placenta Location….…………………………
36
figure 4.3 Mode of Delivery and Placenta Location……………….………… 37
figure 4.4 Gestational Hypertension and the Placenta Location……………... 38
figure 4.5 Number of Pregnancies and the Placenta Location….…………… 39
figure 4.6 Fetal Presentation and the Placenta Location…………………… 40
figure 4.7 Gestational Age per Week and the Placenta Location…………… 41
figure 4.8 Estimated Fetal Weight and the Placenta Location……............... 42
figure 4.9 Amniotic Fluid Volume and the Placenta Location………………. 43
IX
List of Abbreviations
AFV Amniotic Fluid Volume
BPD Biparietal Diameter
C/S Caesarean Section
EFW/KG Estimated Fetal Weight per Kilogram
FL Femur Length
HC Head Circumference
KG Kilogram
MA Maternal Age
MVP Maximum Vertical Pocket
NSVD Normal Spontaneous Vaginal Delivery
SPSS Statistical Package for Social Science
WKS Weeks
US Ultrasound
1
Chapter One
2
Chapter One
Introduction
Placenta is an important connecting organ between mother and
fetus. classified high or low and anterior or posterior categories
if placenta implanted on the lower segment of the uterus is
called low lying placenta(1).
Both the American College of Obstetricians and Gynecologists
and the American Institute of Ultrasound in Medicine
recommended that the standard obstetric sonogram in the second
and/or third trimester should include the evaluation of placental
position and morphology, the estimation of amniotic fluid
volume, and the evaluation of both the morphology and function
of the umbilical cord( 2).
In most pregnancies, implantation occurs in the upper portion of
the fundus. It has been found that 37% of placentas attach
anteriorly, 24% posteriorly, and 34% in fundal position ( 3).
Placental position and morphology may change considerably
during pregnancy. If the area of implantation is less than optimal
for placental development, the placenta moves to a more suitable
region of the endometrium for adequate blood supply( 3).
Parts of the placenta located in less favourable positions atrophy
with time. For example, low implantation of the placenta occurs
frequently in early pregnancy, but this may change through
differential growth of the placenta and uterus( 3). The
relationship between placental morphology (placental width,
volume, and circumference), fetal development, and pregnancy -
related complications has been investigated previously ( 3).
3
However, the relationship between placental localisation, birth
weight, and Doppler parameters is less known. Lateral placenta
may predispose certain women to uteroplacental insufficiency
and low birth weight(3). Similarly, the blood supply of the
anterior and posterior parts of the uterus may differ, possibly
causing differences in birth weight and Doppler parameters (3).
While abnormalities in amniotic fluid volume and umbilical cord
Doppler velocimetry immediately alert the sonogra pher
(possible implications on the continuation of physiological
pregnancy), sonographic assessment of placental location , after
exclusion of previa or marginal insertion (necessary to assess
the option of vaginal delivery), is often limited to a mere
notional description without any link to possible implications on
pregnancy and childbirth ( 2).
There is a relative paucity of data regarding Placental Location.
Furthermore, studies of its association with specific obstetric
complications have reached contradictory conclusions and no
consensus has yet been achieved regarding the relationship
between Placental Location and non-vertex fetal presentation at
term(2).
1.1 Statement of the Research Problem:
The placenta is an organ connecting the developing fetus to the
uterine wall to allow nutrient uptake, waste elimination, and gas
exchange via the mother's blood supply(4).
Location of the placenta within the uterus is likely important
determinants of placental blood flow, fetal presentation, and
therefore pregnancy success . Thus, this study is intended in such
a way that it targets to study the different positions of placenta.
4
1.2.Objectives:
General objectives:-
To study the placental location in the third trimester using
ultrasound, in order to find the most prevalent placental
location.
Specific objectives:-
To find sites of Placental Location and its effect on fetal
presentation.
To find the effect of certain pregnancy complications on
Placental Location.
To find the effect of placental location on the estimated
fetal weight and the amniotic fluid volume.
1.3.Organisation of the Research
This research consists of five Chapters. Chapter one covers
the introduction which contains (Statement of the research
problem, Objective of the study, Research methodology and the
Organisation of the research). Chapter two explains literature
review which takes account of (Anatomy, Physiology, Pathology,
Sonographic appearance and Sonographic pathology of the
placenta location and previous studies relevant to this research).
Chapter three explore research methodology. Chapter four
discovers result and data analysis. And chapter five presents
discussion, conclusion and recommenda tions.
5
Chapter Two
6
Chapter Two
Background and Literature Review
2.1: placenta anatomy
2.1.1. Development:
The placenta is the organ responsible for providing endocrine secretions
and selective transfer of substances to and from the fetus. It serves as an
interface between the mother and developing fetus. Understanding the
development of the placenta is important, as it is the placental
trophoblasts that are critical for a successful pregnancy (5).
By day 3 or 4 after fertilization, the embryo consists of about 100 cells
and floats free in the uterus While the blastocyst floats in the uterine
cavity for two to three days, it is nourished by the glycogen -rich uterine
secretions. Then, some six to seven days after ovulation, given a
properly prepared endometrium, implantation begins (6).
When it implants into the maternal decidua and develops villous
projections for gaseous exchange and the transfer of nutrients from the
maternal circulation. At about 9weeks differentiates into the chorionic
leave (smooth) which becomes membranous fusing with the amnion
and chorion frondosum (frond-like) which becomes true placenta (7).
The invading trophoblast penetrates endometrial blood vessels forming
intertrophoblastic maternal blood-filled sinuses . Blood pools known
as lacunae that form as maternal capillaries erode nourish the
proliferating trophoblastic cells.
A primitive is formed, and the lacunae and trophoblastic cells develop
into a mature placental/maternal circulation complex that will sustain
the pregnancy(1 6) blood exchange network between mother and
conceptus
7
Trophoblastic cells advance as early or primitive villi, each consisting
of cytotrophoblast surrounded by the syncytium. Simultaneously, the
lacunar spaces become confluent with one another and, by weeks 3 –4,
form a multilocular receptacle lined by syncytium and filled with
maternal blood: this becomes the future intervillous space. With
further growth of the embryo the decidua capsularis becomes thinner,
and both villi and the lacunar spaces in the decidua are obliterated,
converting the chorion into chorion ic levae. The villi in the chorionic
frondosum show exuberant division and subdivision, and with the
accompanying proliferation of the deciduas basalis, the future placenta
is formed. This process starts at 6wks and the definitive numbers of
stem villi are established by 12wks (5).
Fig 2.1: Diagrammatic representation of the development of the placenta
during the first 21 days of gestation (8).
Placental growth continues to term. Until week 16, the placenta grows
both in thickness and circumference due to growth of the chorionic villi
with accompanying expansion of the intervillous space. After 16wks
growth occurs mainly circumferentially (1 7).
2.1.2: Structure:
Typically, at term placenta weighs nearly a pound (500g), 20cm to 22cm
long and is 2cm to 2.5cm thick. It is dark maroon in colour in the
8
maternal side and shiny translucent gray in colour in foetal side. It is
attached to the foetus by the umbilical cord. (2 1).
Occupies 30% of the uterine wall at term and has two surfaces:
Fetal surface: Covered by a smooth, glistening amnion with the
umbilical cord usually attached at or near its centre. Branches of the
umbilical blood vessels are visible beneath amnion as they radiate from
the insertion of the cord(5).
Maternal surface: Rough and spongy appearance, divided into bumps
cotyledons (15–20) by septa arising from the maternal tissues. Each
cotyledon may be supplied by its own spiral artery. Numerous small
greyish spots may be visible on the maternal surface representing
calcium deposition in degenerated areas (5). The placental membranes
are composed of the amnion and chorion. The amnion is first
identifiable about the seventh or eighth day of embryonic development
and eventually engulfs the growing embryo. As the pregnancy
progresses the amnion is brought into contact with the chorion. This
occurs at approximately twelve to fifteen weeks gestation. The placental
parenchyma is composed of a stromal compartment that is filled with
vascular and lymphatic channels. The stroma eventually becomes
slightly elevated with convex areas called lobes which are incompletely
separated by grooves. The number of lobes varies from 10 to 38 and the
number remains the same throughout gestation (1 3).
9
2.1.3:Umbilical cord
Umbilical cord is usually 1 to 2cm in diameter and the length of
the cord Varies from 30 to 90cm recent study by Bulkawade et al
suggested that the length may vary 24 to 124cm normally (1 4)
Vascular cable that connects the fetus to the placenta covered by
amniotic epithelium contains two umbilical arteries and one umbilical
vein embedded into the Wharton’s jelly.
Arteries carry deoxygenated blood from fetus to placenta and the
oxygenated blood returns to fetus via the umbilical vein. In a full -term
fetus, blood flow in the cord approximate ly is 350mL/min (5).
2.1.4: Cord Insertion:
The placental cord insertion site should be sought and documented.
According to the literature, the placental cord insertion site may be
visualized with real -time ultrasound between 50-60% of pregnancies in
routine clinical practice and over 95% of cases w ith colour Doppler (9).
The placental cord insertion site is most difficult to assess when the
placenta is posterior and in the presence of oligohydramnios. The
umbilical cord normally inserts near the center of the placenta.
A cord which appears to insert near the edge of the placenta is called a
marginal insertion or battledore placenta and is generally thought to be
of no concern (9).
A cord which fails to reach the placenta and inserts in the membranes is
known as a velamentous insertion and may complicate the pregnancy
especially if the intramembranous umbilical vessels are close to or cross
the internal os (a condition known as vasa previa) (9).
10
Fig:2.2 Normal Cord Insertion Sonogram of the uterus shows a
posterior placenta with a central umbilical cord insertion ( 9).
2.1.5:Placental circulation
The placental circulation brings into close relationship two circulation
systemes the maternal and the fetal. The supply of blood to the placenta
is influenced by various factors, especially by the arterial blood
pressure, uterine contractions, tobacco abuse, medications and
hormones. Placental blood flow is increased at term and amounts to 500
ml/min (80% of the uterine perfusion). (1 5).
Uteroplacental circulation is the maternal blood circulating through the
intervillous space . Intervillous blood flow at term is estimated to be
500–600mL/min, and blood in the intervillous space is replaced 3 –4
times/min. Pressure and concentration gradients between fe tal
capillaries and intervillous space favours placental transfer of oxygen
and other nutrients to the fetus (5). Spiral arteries respond to the increase
demand of blood supply to the placental bed by becoming low -pressure,
high-flow vessels.
11
They become tortuous, dilated, and less elastic by trophoblastic
invasion, which starts early in pregnancy and occurs in two stages, in
first trimester, the decidual segments of the spiral arterioles are
structurally modified,in second trimester, second wave of troph oblastic
invasion occurs, resulting in invasion of myometrial segments of spiral
arteries. Failure of this physiological change, particularly second wave
of trophoblastic invasion, is implicated in development of preeclampsia
and intrauterine growth restri ction (5).
Blood entering the intervillous space from the spiral artery becomes
dispersed to reach the chorionic plate and gradually the basal plate,
being facilitated by mild movements of villi and uterine contractions
(1 7).
From basal plate, uterine veins drain the deoxygenated blood. Venous
drainage only occurs during uterine relaxation (5). Spiral arteries are
perpendicular and veins are parallel to uterine wall, making large
volumes of blood available for exchange at the intervillous space even
though the rate of flow is decreased during contraction, i.e. the veins
are blocked for a longer time to allow pooling of blood in the
retroplacental area (5).
Two umbilical arteries carry deoxygenated blood from the fetus and
enter the chorionic plate underneath the amnion (5). Arteries divide into
small branches and enter the stem of the chorionic villi, where further
division to arterioles and capillaries occurs (5). The blood then flows to
the corresponding venous channel and subsequently to the umbilical
vein. Maternal and fetal bloodstreams flow side by side, in opposite
directions, facilitating exchange between mother and fetus (5).
Oxygenated and nutrient -rich fetal blood passes from the fetal capillary
bed in the villi to an enlarging system of veins that eventually converge
to form a single umbilical vein in the umbilical cord(9).
12
In the fetal abdomen, the umbilical vein courses cranially towards the
liver where it joins the portal sinus (umbilical portion of the left portal
vein) to supply the liver.
Most of the fetal blood bypasses the liver via the ductus venosus which
originates at the portal sinus and terminates in the inferior vena cava or
left hepatic vein (9). Deoxygenated blood returns from the fetus to the
placenta via two umbilical arteries which originate at the right and left
internal iliac arteries in the fetal pelvis. The two umbilical arteries
divide into numerous radiating branches as the cord inserts in the
placenta (9).
Fig 2.3: Fetal and maternal circulation (9).
13
2.2: Physiology
The placenta receives and transmits endocrine signals between the
mother and fetus and is the site of nutrient and waste exchange. The
total placental surface area for exchange is 11 m 2 at term. (1 8).
The placenta is a metabolically active organ and manages to extract 40 –
60% of the total glucose and oxygen supplied by the uterine circulation.
Various nutrients and metabolites are transferred across the placenta to
the fetus by passive diffusion (oxygen,carbon dioxide, urea, fatty acids),
facilitated diffusion(glucose, lactate), active transport (amino acids,
fatty acids), as well as endocytosis or exocytosis (8).Facilitated diffusion
involves transfer down a concentration gradient by a carrier molecule
without the requirement of additional energy. Active transport, in
contrast, requires both carrier proteins and additional energy. In
general, placental transfer increases throughout gestation as the fetal
growth rate increases (8).
As an active endocrine organ, the placen ta produces a number of
hormones, growth factors, and cytokines. The production of human
chorionic gonadotrophin (hCG), oestrogens, and progesterone by the
placenta is vital for the maintenance of pregnancy (8).The placenta acts
as a barrier for the fetus against pathogens and the maternal immune
system(5).
The placenta forms an effective barrier against most maternal blood -
borne bacterial infections. However, some important organisms, such as
syphilis, parvovirus, hepatitis B and C, rubella, human immune
deficiency virus (HIV), and cytomegalovirus (CMV) are able to cross it
and infect the fetus during pregnancy(5).
Many drugs administered to the mother will pass across the placenta
into the fetus; exceptions include low-molecular-weight heparin
(LMWH).
14
Some drugs may have little effect on the fetus and be considered ‘safe’
(e.g. paracetamol), but others (e.g. warfarin) may significantly affect
development, structure, and function of the fetus —a process known as
teratogenesis (5).
2-3: Ultrasound Evaluation of placenta
Ultrasonography is the preferred technique for placental localization. It
permits a comparatively precise estimate of the separation of the lower
placental margin and internal cervical os (12).
.General evaluation of the placenta sh ould be a routine part of every
second and third trimester ultrasound study as indicated in the American
Institute of Ultrasound in Medicine Antepartum Obstetrical Ultrasound
Examination Guidelines ("The placental location, appearance, and its
relationship to the internal cervical os should be recorded") (9).
Routine evaluation of the placenta with colour Doppler is now favoured
to rapidly find the placental cord insertion site and to detect vascular
abnormalities in the placenta and the retroplacental uterine wall (9).
This is especially important if the placenta is anterior and appears to be
low-lying or previa since the risk of placenta acreta is highest in this
situation. An important view is the median lower segment and cervix
image which may ident ify vasa previa associated with velamentous
insertion of the cord or succenturiate lobe (9).
2.3.1: Location:
The reliability of ultrasonographic localization of the placental site has
been tested in many different ways (1 9). The placenta may be described
as predominantly anterior, posterior, fundal, right or left lateral. A
placenta that is distant from the internal os may be described as being in
a normal location, central, or non previa (9).
15
A low-lying placenta describes a placenta which appears to exten d into
the lower uterine segment and is within 1 -2 cm of the internal os. A
placenta previa describes a placenta which appears to partly or
completely cover the internalos. Documentation should include an image
showing placental location and the relationsh ip to the internal os (9).
Fig.2.4 :Normal Early Placenta Longitudinal TAS image of the uterus (bladder is
empty) shows a normal anterior placenta (1) and a retro placental FMC.
2.3.2: placenta Echo Texture
The normal placenta appears as a sonographically uniform structure
with mid amplitude echoes (in contrast, the adjacent uterine wall
(decidua and myometrium) appear less echogenic or hypoechoic). In the
third trimester, the placenta generally appears less homogeneous and
may have small anechoic or hypoechoic areas of different pathological
etiologies. Calcium deposits are seen in the majority of placentas in the
third trimester and appear as high amplitude (white) linear echoes (9).
16
Fig.2.5 : Normal Anterior Placenta TAS image at 19 weeks gestation shows a
normal anterior placenta extending into the lower segment of the uterus. Note the
normal hypoechoic uterine wall sandwiched between the placenta and the bladder
wall .
2-3-4: Retroplacental Uterine Wall
The retroplacental uterine wall consists of the richly vascular
myometrium and decidua basalis. These tissues are distinctly
hypoechoic in comparison to the placenta (9). After 18 weeks gestation,
the normal anterior retroplacental uterine wall (sometimes referred to as
the subplacental complex or the retroplacental space) has an average
thickness of 9.5 mm(. The sonographic diagnosis of placental creta
depends on this normal hypoechoic zone being invaded by more
echogenic villi and appearing thinner or not seen. The endometr ial veins
in the decidua basalis may be quite dilated and appear as irregular,
tubular spaces especially when the placenta is posterior (probably due to
diminished venous drainage when the patient is supine and the weight of
the uterus on the posterior ute rine wall impedes venous flow)(9).
Other retroplacental abnormalities include hematomas associated with
abruption of the placenta and fibroids which must be distinguished from
focal myometrial contractions (9).
17
Fig2.6 Retroplacental Complex Sagit tal TAS image of a posterior placenta (1)
shows a prominent retroplacental complex and the "end" of a FMC(3). ( 9).
2-4: Normal Variants
Typically, the placenta is located along the anterior or posterior
uterine wall, extending into the lateral walls. Although usually
discoid, the placenta can be variable in morphology. Variant
placental shapes include: bilobed is a Placenta with two
relatively even sized lobes connected by a thin bridge of
placental tissue, succenturiate An additional lobule separate
from the main bulk of the placenta , circumvallate Chorionic
plate smaller than the basal plate with associated rolled
placental edges, and placenta membranacea Thin membranous
structure circumferentially occupying the entire periphery of the
chorion (10).
18
Fig.2.7: Bilobed placenta. (a) Diagram shows a bilobed placenta. (b) US
image shows a bilobed placenta. The two lobes of the placenta ( P1 and
P2) are separated by a thin bridge of placental t issue that covers the
internal os. In this case, the umbilical cord (arrowhead) inserts into the
bridge of t issue (1 0) .
Fig.2.8: Succenturiate placenta. (a) Diagram shows a placenta with a
succenturiate lobe. (b) US image shows aplacenta (P) with a succenturiate lobe
(S) . The main body of the placenta is located along the posterior uterine wall . A
second soft -t issue st ructure of the same echogenicity but located anteriorly is the
succenturiate lobe(1 0).
19
Fig.2.9: Circumval late placenta. (a) Diagram shows a ci rcumvallate
placenta. (b) US image shows a ci rcumvallate placenta. The chorionic
plate (the fetal surface of the placenta) (black arrowheads) is smaller
than the basal plate (the surface interfacing with the uterus), with roll ing
and shouldering of the placental margins (white arrowheads). F =
fetus(1 0).
Fig.2.10 (a) Diagram shows a placenta membranacea. (b) Velamentous
insert ion of the umbilical cord. Doppler US image shows insert ion (I)
(white arrow) of the umbilical cord into a thin membrane of t issue
extending from the margin (black arrow) of the place nta (P) (1 0).
20
2.5: Pathology of placenta
2.5.1:Placental infarction
A placental infarction refers to a localised area of ischaemic
villous necrosis. It is a significant cause of placental
insufficiency. A localized infarction can occurs in up to 12.5%
(range 5-20%) of all gestations. It usually results from an
interrupted maternal blood supply (11). Placental infarcts are
more common at periphery of placenta. Most placental infarcts
are difficult to diagnose on ultrasound (11). They may on
occasion be seen as a hypoechoic region with thick hyperechoic
rim (11).
2.5.2 :Placental Causes of Antepartum Hemorrhage
Sonographically, placental hematomas may be difficult to distinguish
from subchorionic hemorrhages. Placental hematomas do not cause
symptoms, bleeding, or spotting because they are within the chorionic
sac and have no communication with the endometrium (11)
Antepartum hemorrhage (vaginal bleeding between 20 weeks
gestation and delivery) remains an important cause of maternal
and fetal morbidity and mortality.
Placenta previa and placental abruption account for more than
one half of cases of antepartum hemorrhage and a re increasing
in prevalence as the rate of cesarean section increases (1 0).
2.5.3 Placental Abruption
Placental abruption represents premature separation of the
placenta from the uterine wall. Although rare (<1% of
pregnancies), third-trimester abruption is associated with an
increased risk of preterm delivery and fetal death (1 0).
21
US is frequently performed to confirm the presence of abruption
and assess the extent of subchorionic or retroplacental
hematoma. The presence of blood in large enough volumes to be
visible sonographically indicates retained hemorrhage that may
remain symptomatic (1 0).
False-negative results can occur when blood dissects out from
beneath the placenta and drains through the cervix (10).
Fig 2.11:US image shows placental abruption. A crescenteric collection
of predominantly hypoechoic fluid l i fts the edge of the placenta (P) away
from the underlying myometrium (M) .
The fluid collection contains layering high -attenuation material
(arrowhead), a finding consistent with blood (1 0).
2.5.4 Placenta Previa
Placenta previa refers to abnormal implantation of the placenta
in the lower uterine segment, overlying or near the internal
cervical os. Normally, the lower placental edge should be at
least 2 cm from the margin of the internal cervical os (1 0).
The relationship of the placenta to the internal os changes
throughout the course of pregnancy as the uterus enlarges (1 0).
22
The prevalence has been estimated to be approximately 0.5% of
all pregnancies(11).It is a major cause of antepartum and
intrapartum hemorrhage; maternal morbidity and mortality ;
preterm delivery and neonatal mortality( 5).
Placenta previa is associated with a number of risk factors,
including: previous placenta previa, previous caesarean section,
old maternal age, multiparity, large placentas (11).
It is divided into 4 grades depending on the relationship and
distance to the internal os (11).
grade I - low lying placenta - placenta lies in lower uterine
segment but its lower edge does not reach up -to internal cervical
os (11).
grade II - marginal previa - placental tissue reaches the margin
of the internal cervical os, but does not cover it (11).
grade III - partial previa - placenta partially covers the internal
cervical os(11) .
grade IV - complete previa - placenta completely covers the
internal cervical os(11).
Sometimes types I and II are termed a minor or partial placenta
previa and types III and IV termed a major placenta previa (11).The
diagnosis of placenta previa should not be made before 15 weeks
gestation, and low-lying or marginal placental positioning should be
reevaluated later in gestation to confirm placental position before
delivery(1 0).Although transvaginal sonography is the imaging
standard for making this diagnosis, the position of the placenta is
usually demonstrable with transabdominal imaging (1 0).Transvaginal
or translabial approaches may be required to accurately demonstrate
the location of the placenta, particularly in posteriorly locat ed
placentas .
23
However, transvaginal imaging should be undertaken with care in
advanced pregnancies, as it can lead to premature rupture of
membranes or to infection when the membranes have already
ruptured(1 0).
Fig. 2.12: : Spectrum of placenta previa Transvaginal US image shows in
(a) : a low-lying placenta , (b): The placental margin comes to the
internal cervical os but does not cover i t , (c): The placenta entirely
covers the internal cervical os, (d): the posterior placenta ent irely covers
the internal cervical os(11).
24
2.5.5: Vasa Previa
Vasa previa refers to the presence of abnormal fetal vessels
within the amniotic membranes that cross the internal cervical
os. These vessels are unsupported by Wharton jelly or placental
tissue and are at risk of rupture when the supporting membranes
rupture; such vessels are also at risk of direct injury during
labor. Rupture of these vessels can lead to catastrophic fetal
hemorrhage (1 0).
In cases of vasa previa, the abnormal vessels either connect a
velamentous cord insertion with the main body of the placenta
or connect portions of a bilobed placenta or a placenta with a
succenturiate lobe . Given this association, vasa prev ia needs to
be excluded in patients with variant placental morphology. The
diagnosis of vasa previa is made with Doppler US, which
demonstrates vascular flow within vessels overlying the internal
cervical os (1 0).Occasionally, transvaginal US is required to
confirm the presence of these aberrant vessels. Marginal sinus
previa, where prominent maternal vessels are appreciated at the
edge of the placenta, can mimic vasa previa at color flow
imaging. As with placenta previa, patients with vasa previa
diagnosed in the second trimester should be reevaluated later in
gestation. The vasa previa can resolve as the uterus enlarges and
the relationship of the placenta to the internal os changes (1 0).
25
Fig2.13 :Transvaginal power Doppler US image obtained at 18 weeks
gestation shows an anterior placenta (P) . There is vascular flow in a
vessel (V) that is closely applied to the internal cervical os (O) . Follow-
up US at 32 weeks gestation showed resolution of the vasa previa, t hus
allowing subsequent uneventful vaginal delivery (1 0).
2.5.6: Placental Hematoma
Placental hematomas can occur on the fetal (preplacental or
subchorionic) side or maternal (retroplacental) side or be
centered within the placenta. At US, placental hemato mas
appear as well-circumscribed masses with echogenicity that
varies according to chronicity (1 0). They are hypoechoic or
anechoic in the acute phase, heterogeneously echogenic in the
subacute phase, and anechoic in the chronic phase. Doppler
interrogation should reveal absence of internal blood flow; this
finding allows differentiation of hematomas from other placental
masses(1 0).
26
Fig2.14: image shows a rounded collection of mixed -echogenicity
material (arrowheads) deep to the chorion along the lateral margin of the
placenta. There is no internal Doppler s ignal tosuggest blood flow. This
appearance is consis tent with a subchorionic hematoma(1 0).
2.5.7 Morbidly adherent placenta
During the process of placental development and implantation, a
defect in the normal deciduas basalis from prior surgery or
instrumentation allows abnormal adherence or penetration of the
chorionic villi to or into the uterine wall (1 0). The extent of
adherence to and invasion of the placental tissue varies:
Superficial invasion of the basalis layer is te rmed placenta
accreta (approximately75% of cases); deeper invasion of the
myometrium is termed placenta increta; and even deeper
invasion involving the serosa or adjacent pelvic organs is termed
placenta percreta (1 0) . This abnormal adherence of the placenta
to the uterus can result in catastrophic intrapartum hemorrhage
at the time of placental delivery, often necessitating emergent
hysterectomy (1 0).
27
Gray-scale US and Doppler imaging have been shown to be
effective imaging strategies for the detection of placenta accreta
when applied to a clinically high -risk population, such as those
with prior uterine surgery or placenta previa (1 0). Sonographic
features of placenta accreta include loss of the normal
retroplacental clear space, anomalies of the bladder -myometrium
interface, prominent placental lacunae, and increased vascularity
at the interface of the uterus and bladder (10). Of these various
sonographic features, the presence of prominent placental
lacunae has the highest positive predictive value (. Lacunae are
characterized by ill -defined margins, irregular shape, and
turbulent flow (1 0).
Fig.2.15 :US images show disruption of the normal hypoechoic
myometrium (black arrowheads) by invading placental t issue (white
arrowheads). B = bladder, P = placenta(1 0).
28
2.5.8 Placental Tumours
Non trophoblastic placental tumors are quite rare.
Chorioangiomas are the most common, occurring in less than 1%
of pregnancies . Placental teratomas are extremely rare and are
similar in appearance to chorioangiomas, but are differentiated
by the presence of calcifications .Melanoma is reported to be the
most common tumour to metastasize to the placenta (10).
2.6 Previous studies:
Gizzo et al.International Journal of Clinical and Experimental
Medecine (2015). Assessed sonography of placental location: a
mere notional description or an important key to improve both
pregnancy and perinatal obstetrical care? A large cohort study .
“We conducted an observational -prospective-cohort study on
pregnant women referred to the Ob/Gyn Unit of Padua
University for routine third-trimester ultrasound scan. For all
eligible patients we evaluated the correlation between sites of
PL and perinatal maternal/fetal outcomes. Non-cephalic
presentation was found in 1.4% of anterior, 8.9% of posterior,
6.2% of fundal and 7.2% of lateral insertions. FP at the
beginning of the third trimester as opposed to presentation at
birth was concordant in 90.3% of anteri or, 63.3% of posterior
and 76.5% of lateral insertions. Considering only non -cephalic
fetuses we observed a decreasing probability for spontaneous
rotation in the following lies: 88% anterior -PL, 80% posterior-
PL, 77% lateral-PL, and 70% fundal-PL. Patients with posterior-
PL (significantly associated with previous -CS) had a
significantly higher CS-rate (due to previous-CS and breech-
presentation).
29
Significant differences were found in terms of gestational -
hypertension and fresh-placental-weight between different sites
of PL. In conclusion our data showed that an understanding of
the role that PL plays in influencing the incidence of certain
maternal-fetal conditions may assist Clinicians in improving
perinatal maternal/fetal outcomes” . (2)
Ozoko et al. Ultrasonographic Study of Placenta Positioning and
Its Significance in Parturition among Women in Delta (2014)
“Ultrasound is a useful adjunct to the physical examination,
particularly in obstetrics patients. By ultrasonography we
visualize the placenta position in -situ and describe various
positioning of placenta in the uterus. The placenta is positioned
at different sites in the uterus which can predict methods of
parturition. The objective of this study is to investigate the
different positions of placenta as seen in ultrasound scan and it’s
significant in parturition among women in Delta state. The study
comprises of 150 women who registered for antenatal care at
Eku Baptist Hospital Eku, Delta state, and have given birth in
the Hospital. The pregnant women were examined with
ultrasound scan which determined the positions of the placenta
at the radio diagnostic department. The different positions such
as anterior, posterior, fundal and previa were recorded. The
methods of deliveries were also taken note of in the pre -
maternal labour forms in obstetrics/gynaecology department and
health record office of the Hospital.
Data were presented as mean and standard deviation; data were
analysed using statistical package for social scie nce (SPSS).
30
The cases of previa were related to the type of delivery out of 28
cases of previa 18 women delivered by caesarean section and 10
had normal delivery. 10 out of all are previa type I, 7 are previa
type II, and 11 are previa type III. All type III cases delivered
through caesarean section” . (2 0)
31
Chapter Three
32
Chapter Three
Methodology
3-1: Design of the Study
This research is a descriptive cross-sectional study about the normal
position of the placental location using ultrasound.
3-2: Population of the Study.
One hundred pregnant women have been examined by utilizing
ultrasound scan.
Pregnant women with gestational period of the Third Trimester are
included.
This research was preceded at Omdurman Maternal Hospital.
This study was conducted in a period of three months – from October
up to December 2017.
3-3: Method of Data Collection.
The data of this research was collected by using special data
collection sheet, which consists of ten variables like: - mother age,
number of featus in pregnancy, gestational age, mode of delivery,
gestational hypertension, gravidity, gestational diabetes, fetal
presentation, estimated fetal weight and amniotic fluid volume.
The research data collected from: -
- Routine referred pregnant women in the third trimester.
- Text books
- Websites
- Data collection sheet .
33
3-4: Techniques utilized .
In general, there was no special preparation like breathing technique
or full Bladder needed. Pregnant mother ought to be in supine
position; transabdominal convex transducer was used with frequency
of 3.5 MHz and ultrasound gel. During the ultrasound examination
FL, BPD, abdomen circumference (AC) and the placental location
were assessed in longitudinal section at the point of umbilical cord
insertion to display the placental site properly.
3-5: Data Analysis.
The data of this study was illustrated by figures and tables using
Excel Data Analyses and interpreted by SPSS system.
3-6: Ethical Approval.
Written permission taken from the administration of the research
department at the Omdurman Maternal Hospital.
No patient details were disclosed.
34
Chapter Four
35
Chapter Four
Results
Table 4-1: Cross-Tabulation of Age and Placenta Location.
Age Anterior Posterior Fundal Total
15 - 19 4 4 0 8
20- 24 10 8 0 18
25-29 20 17 0 37
30- 34 10 9 1 20
35-39 11 3 1 15
40-44 1 1 0 2
Total 56 42 2 100
Figure 4-1: Cross-Tabulation of Age and Placenta Location.
0
5
10
15
20
25
15-19 20-24 25-29 30-34 35-39 40-44
Anterior
Posterior
Fundal
36
Table 4-2: Cross-Tabulation of the Gravidity and Placenta Location.
Gravida Anterior Posterior Fundal Total
1 upto 2 25 15 0 40
3 upto 4 17 17 0 34
5 upto 6 6 7 1 14
7 upto 8 4 1 1 6
9 upto 10 4 2 0 6
Total 56 42 2 100
Figure 4-2: Cross-Tabulation of Gravidity and Placenta Location.
0
5
10
15
20
25
30
1 −2 3 −4 5 −6 7 −8 9 −10
Anterior
Posterior
Fundal
37
Table 4-3: Cross-Tabulation of the Mode of Delivery and Placenta
Location.
Mode of Delivery Anterior posterior Fundal total
C/S 18 15 0 33
NSVD 20 16 1 37
PRIMIGRAVIDA 17 12 1 30
TOTAL 55 43 2 100
Figure 4-3: Cross-Tabulation of the Mode of Delivery and Placenta
Location.
0
5
10
15
20
25
Anterior posterior Fundal
C/S
NSVD
PRIMIGRAVIDA
38
Table 4-4: Cross-Tabulation of Gestational Hypertension and Placenta
Location.
Hypertension Anterior Posterior Fundal Total
Hypertensive 3 4 0 7
Non Hypertensive 53 38 2 93
Total 56 42 2 100
Figure4-4: Cross-Tabulation of Gestational Hypertension and Placenta
Location.
0
10
20
30
40
50
60
Anterior Posterior Fundal
Hypertention
Non-Hypertention
39
Table 4-5: Cross-Tabulation of Gestational Diabetes and Placenta
Location.
Diabetes Anterior Posterior Fundal Total
Diabetic 4 2 0 6
Non-Diabetic 52 40 2 94
Total 56 42 2 100
Figure 4-5: Cross-Tabulation of Gestational Diabetes and Placenta
Location.
0
10
20
30
40
50
60
Anterior Posterior
Diabetic
Non-Diabetic
40
Table 4-6: Cross-Tabulation of the Number of Pregnancies and Placenta
Location.
Situation Anterior Posterior Fundal Total
Single 56 40 2 98
Twins 0 2 0 2
Total 56 42 2 100
Figure 4-6: Cross-Tabulation of the Number of Pregnancies and
Placenta Location.
0
10
20
30
40
50
60
Anterior Posterior Fundal
Single
Twins
41
Table 4-7: Cross-Tabulation of the Fetal Presentation and the Placenta
Location.
Featal Presentaion Anterior Posterior Fundal Total
Cephalic 51 39 2 92
Breech 5 3 0 8
TOTAL 56 42 2 100
Figure 4-7: Cross-Tabulation of the Fetal Presentation and the Placenta
Location.
0
10
20
30
40
50
60
Anterior Posterior Fundal
Cephalic
Breech
42
Table 4-8 Cross-Tabulation of Estimated Fetal Weight and The Placenta
Location in the GA of 35 Wks.
EFW/kg Anterior Posterior Fundal Total
2.1 - 2.5kg 4 1 1 6
2.6 - 3.0kg 1 1 1 3
3.1 - 3.5kg 1 1 2
3.6 - 4.0kg 1 1
Total 7 3 2 12
Figure 4-8 Cross-Tabulation of Estimated Fetal Weight and The
Placenta Location in the GA of 35 Wks.
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
2.1 - 2.5kg 2.6 - 3.0kg 3.1 - 3.5kg 3.6 - 4.0kg
Anteriro
Posterior
Fundal
43
Table 4-9: Cross-Tabulation of the Amniotic Fluid Volume and the
Placenta Location.
TYPE Anterior Posterior Fundal Total
Average 54 41 2 97
Oligohydramnios 2 0 0 2
Polyhydramnios 0 1 0 1
TOTAL 56 42 2 100
Figure 4-9: Cross-Tabulation of the Amniotic Fluid Volume and the
Placenta Location.
0
10
20
30
40
50
60
Anterior Posterior Fundal
Average
Oligohydramnios
Polyhydramnios
44
Chapter Five
45
Chapter Five
Discussion, conclusion and recommendations
5-1. Discussion
The placenta is considered as a fetal organ. It presents an
indirect relationship between the maternal distribution and
that of the fetus and serves as the organ for exchange of
nutrients, gases and waste products through diffusion.
Ultrasonography is the ideal technique for placental
locataion.
The main objective of this research is intended to highlight
the placenta location for the pregnant mother in the third
trimester. It comprehended one hundred pregnant mothers
whose average ages were 28.52±6.17 years of anterior,
27.24±5.73 years of posterior and 34.50±3.53 of fundal, this
age constitutes 37% of the sample (table 4 -1 and figure 4-
1). The result showed that the primigravida and
secundigravida comprise 40% of the study, at 25% of
anterior and 15% of posterior (table 4-2 and figure 4-2). It
was observed during the study that the averages of placenta
location were: 18.33±1.53 of anterior, 14.33±2.08 of
posterior and 0.67±0.58 of fundal localization as illustrated
all the tables. According to the mode of delivery it was
noted that the averages were: - 11±9.64, 12.33±10.02 and
10±8.18 c/s, nsvd and Primigravida respectively (Table4 -3
and the figure 4-3).
46
The pregnant mothers who had hypertension formed only
7% of the sample, 3% of anterior and 4% of posterior (table
4-4 and figure 4-4).
And the mothers who have had diabetes constituted only 6%
of the sample study 4% of anterior and 2% of posterior
(table 4-5 and figure 4-5).
During the research period it was noted that the 38wks
were the most frequent week, which constitute 20% of the
sample size (table 4-8 and figure 4-8). It was also spotted
that the fetal presentation was 92% of cephalic and only 8%
of breech. The most weights seen during this study were
3.1-3.5kg, which compose 32% of the population studied
(table 4-9 and figure 4-9).Amniotic fluid volume was
dividedas 32.33±27.06 average, 0.67±1.16 , oligohydramnios
and0.33±0.57 polihydramnios(table 4 -10 and figure 4-10).
Gizzo et al.International Journal of Clinical and
Experimental Medecine (2015). observed that Cephalic
constitute 88% of anterior, 80% of posterior and70% of
fundal. While the current study showed that cephalic
represent 51% of anterior,39% of posterior and 2% of fundal
PL. But the current study observed that there is no any
association between previous c/s and Placenta location. This
data that breech constitute 5% of Anterior, 3% of posterior
and no fundal seen, whereas the previous showed that the
breech constititute 1.4& of Ante rior, 8.9% of posterior and
6.2% of fundal. (2)
47
Ozoko, et al .Ultrasonographic Study of Placenta Positioning
and Its Significance in Parturition among Women in Delta
State, Nigeria (2014). Analaysed the different positions
such as anterior, posterior, fundal and previa, but the previa
does not include in the current study. (2 0)
48
5-2. Conclusion
In this research covered 100 pregnant mother in the third
trimester, the most placenta 56% located in anterior, while 42%
located in posterior and only 2% located in fundal. During the
study, it was observed that the most ages 37% were the group
ages between 25-29yrs. Another prospect of this study was that
the fetal weights were found to be highest in cases of anterior
placentation, while lowest in cases of fundal placentation. Most
of the AFV 97% was normal-average; only 2% were
oligohydramnios of anterior, while only 1% was polihydramnios
of posterior placentation. In terms of gestational age the week
38 was the most weeks seen composing 20% of the sample size,
9% of anterior and 11% of posterior placental location. For the
fetal presentation, the cephalic constitutes 92%, 51% of it was
anterior, 39% of it was posterior and only 2% was fundal
placentation, whereas breech composes 8% of the sample, 5% of
it was anterior, and 3% was posterior. With regard to the
previous delivery status, it was seen that t he 33% was C/S, 37%
was NSVD and 30% was primigravidity. Regarding to the
number of pregnancies, it was seen that the only 2% was twins
at posterior placentation , and 98% was single, dividing into
56% of anterior, 40% of posterior and 2% of fundal locatio n of
placenta. It is found that 7% of the sample size had
hypertension, at 3% of anterior and 4% of posterior. It was also
obtained that the pregnant mother who had diabetes constitute
only 6% of the sample size, which 4% of it was anterior and 2%
of it was posterior placental location.
49
5-3. Recommendations
Based on the above findings and observations, it is
recommended that: -
Assessment of placenta location should be made in order
to follow up both pregnancy and prenatal obstetrical care.
Further studies should be made in order to comprehend if
the placental location has an influence on the amniotic
fluid volume, estimated fetal weight and the maternal
medical conditions, like: - gestational diabetic and
pregnancy induced hypertension.
Further Study should be done using larger sample for
same GA.
In addition to the routine technique of using longitudinal
and transverse of transabdominal scan, the sonographers
should perform a transvaginal scan to assess the placental site more
accurately if there is any doubt about placental position.
50
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52
Appendices
53
Appendix (A)
The National Ribat University
College of Postgraduate Studies and Scientific
Research
Afro-Asian Medical Training Center
Assessment of the Placental Location in the
Third Trimester Using Ultrasound
Data collection sheet
Mother Age
Number of Featus in Pregnancy
Gestational Age
Mode of Previous Delivery
Gestational Hypertension
Gestational Diabetes
Fetal Presentation,
Estimated Fetal Weight
Amniotic Fluid Volume
Gravidity
54
Appendix (B)
Image (1) : Normal Anterior Placenta TAS image at 39 weeks
gestation shows a normal anterior placenta . Taken from
Omdurman Maternity Hospital on 30-10-2017.
55
Image(2) Normal Fundal Placenta TAS image at 33 weeks
gestation shows a normal Fundal placenta extending into the
Posterior of the uterus. Taken from Omdurman Maternity
Hospital on 13-11-2017.
56
Image(3) : Normal Posterior Placenta TAS image at 34 weeks
gestation shows a normal Posterior placenta . Taken from
Omdurman Maternity Hospital on 27-11-2017.
57
Image(4) Normal Posterior Placenta TAS image at 37 weeks
gestation shows a normal Posterior placenta extending into the
lower segment of the uterus. Taken from Omdurman Maternity
Hospital on 27-11-2017.
58
Image(5) Upper posterior Placenta TAS image at 35 weeks
gestation shows Upper Posterior placenta. Taken from
Omdurman Maternity Hospital on 23-11-2017.
59
Image (6) : Normal Anterior Placenta . TAS image at 34 weeks
gestation shows Anterior placenta. Taken from Omdurman
Maternity Hospital on 21-11-2017.
60
Image (7) : Normal Fundal Placenta. TAS image at 34 weeks
gestation shows Normal Fundal placenta. Taken from Omdurman
Maternity Hospital on 04-12-2017.
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Image (8) : Normal Posterior Placenta TAS image at 38 weeks
gestation shows a normal Posterior placenta. Taken from
Omdurman Maternity Hospital on 04-12-2017.
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