Part III: Pregnancy (Normal &Complicated) Outlines Development & physiology of fetus. Normal pregnancy (Physiological& psychological changes) Prenatal care. Nursing care during complications of pregnancy(APH, PIH, GD, UTI, &anemia). Learning Objectives At the end of this chapter, the student should be able to: 1. Explain mitosis and meiosis and differentiate between the two. 2. Describe the processes of spermatogenesis and oogenesis, and how they differ. 3. Explain how the sex of the conceptus is determined. 4. Describe the three developmental stages of pregnancy with regard to beginning and ending periods and major events occurring during each stage. 5. Describe the development of support structures during pregnancy. 6. Name four major functions of amniotic fluid. 7. Discuss three functions of the placenta. 8. List the steps in the process of the exchange of nutrients and wastes between the maternal and fetal bloodstreams. 9. Trace the path of fetal circulation, including the three fetal shunts. 10. Name three categories of teratogens and list examples of each kind. 11. Discuss the threat to pregnancy that occurs with ectopic pregnancy. 12. Differentiate between the types of multifetal pregnancies. DEVELOPMENT OF FOETUS INTRODUCTION:
75
Embed
Part III: Pregnancy (Normal &Complicated) Outlines ...
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Part III: Pregnancy (Normal &Complicated)
Outlines
Development & physiology of fetus.
Normal pregnancy (Physiological& psychological changes) Prenatal care.
Nursing care during complications of pregnancy(APH, PIH, GD, UTI,
&anemia).
Learning Objectives
At the end of this chapter, the student should be able to:
1. Explain mitosis and meiosis and differentiate between the two.
2. Describe the processes of spermatogenesis and oogenesis, and how they
differ.
3. Explain how the sex of the conceptus is determined.
4. Describe the three developmental stages of pregnancy with regard to
beginning and ending periods and major events occurring during each stage.
5. Describe the development of support structures during pregnancy.
6. Name four major functions of amniotic fluid.
7. Discuss three functions of the placenta.
8. List the steps in the process of the exchange of nutrients and wastes between
the maternal and fetal bloodstreams.
9. Trace the path of fetal circulation, including the three fetal shunts.
10. Name three categories of teratogens and list examples of each kind.
11. Discuss the threat to pregnancy that occurs with ectopic pregnancy.
12. Differentiate between the types of multifetal pregnancies.
DEVELOPMENT OF FOETUS
INTRODUCTION:
Life begins at the time fertilization of the ovum
The zygote formed is a single cell which develops into fully formed adult
Prenatal development is the process in which an embryo or fetus gestates
during pregnancy, from fertilization until birth.
Gestation Period
The gestation period of
a) Germinal Period - This begins at fertilization and extends till the third week.
b) Embryonic period – This extend from 4th
~ 8th
week, involving changes in
shape and external appearance.
c) Fetal period – This extends from 3rd
month up to termination of pregnancy.
Development of supportive structures of fetus & Major Events
Fertilization
o Cleavage Division – The process of repeated mitotic division results in
increase of number of cells known as Cleavage give rise to blastomere.
o Formation of morula and blastocyst -blastomere form compact ball called
morula. The centre of morula is inner cell mass.
Blastocyst – The cells of morula continue to divide and forms blastocele.
At this stage zygote is blastocyst. Outer cell is trophoblast and inner cell mass
is embryoblast.
o Implantation of blastocyst – Blastocyst attaches to endometrium and
implantation takes place on 6th ~ 7
th day after fertilization. Now Endometrium
is ready to support the pregnancy, and is now referred as the decidua.
The
Decidua
The corpus luteum continues to produce progesterone which stimulates
secretery activity of endometrial glands and increase the size of blood vessel
and form soft spongy bed.
The layers of Decidua
Basal Layer – Lies above the biometrium. It contains basal portion of glands
Functional Layer – It is through this layer that the cleavage of placental
separation occur
Superficial compact layer – This forms surface of decidua.
After implantation of the blastocyst the decidua is renamed as :
i. Basal decidua – The decidua underneath the blastocyst.
ii. Caspular decidua – It thin superficial layer covering the ovum.
iii. Parietal decidua – the rest of decidua lining the uterine cavity outside the site
of implantation.
Functions
Provides bed for implantation
Supplies nutrition to early stage of growing ovum
Protective function
Formation of germ layer
This is first major event after implantation.
Three layers are formed –
Ectoderm – layer forms skin and nervous system.
Mesoderm – Layer forms bone, muscle, heart and blood vessel.
Endoderm – Forms mucus membrane and glands
The three layer together are known as embryonic plates.
Development of Placenta:
Placenta develops from two sources
- Fetal part from chorionicfrondsumand,
- Maternal part from dduabasalis.
STAGES
Implantation.
Changes to decidua.
Trophoblastic forms chorion.
Chorionic villi are formed i.e. finger like projection.
Villi becomes profuse in the basal decidua and eventually develops into
placenta .
Villi under capsular decidua being less nourished degenerate and forms
chorionic laeve which is origin of chorionic membrane.
Chorionic villus center consist of mesoderm and fetal blood vessel and
branches of umbilical arteries and vein.
Placental Circulation:
Maternal Placental circulation:
The maternal blood through spiral arteries comes to placental bed and
surrounds the inter villus space and from there enters the veins and is drained
by them.
Fetal Placental Circulation:
Fetal blood comes to placenta through umbilical Arteries and enters the
chorionic villi.
Veins from chorionic villi drain into umbilical vein which carries the blood
from fetus to placenta.
Functions of Fetal Placental Circulation
Respiration – Oxygen is obtained and carbon dioxide is excreted through
placenta.
Nutrition - Placenta provides proteins as amino acids, carbohydrates and fats
as fatty acids.
Storage – It stores glucose as glycogen.
Excretion – It gives out carbon dioxide bilirubin urea uric acid
Protection – Prevents entry of microorganism and noxious agent but not drugs
and virus.
Endocrine – Produces human Chorionic Gonadotropin, Estrogen
&Progesterone.
Anatomic Variations
Succenturate Lobe of placenta , Small extra lobe is present.
Circumvallate placenta – in this an opaque ring is seen on fetus surface.
Battle dore insertion of cord – in this umbilical cord is attached closed to
margin of placenta
Velamentous insertion of chord – Chord is inserted into membrane some
distance away from edge of placenta.
Placenta preavia- Implantation in the lower part of uterine cavity.
Bipartite Placenta – to complete and separate lobes are present
Tripartrite Placenta – Three lobes are present
Umbilical Cord
The umbilical cord or funis forms the connecting link between the fetus and
placenta.
It has two arteries and one vein.
It is protected by Wharton's jelly average length 50 cm
If cord is long may become wrapped around the neck or body of fetus
Amniotic Fluid
The source is through both fetal and maternal
It is secreted by amnion
Some fluid is oozed from maternal vessel and some from fetal vessel
Fetal urine also contributes after 10th week of gestation
It is clear, pale, straw colored fluid consisting 99% of water.
Functions of Amniotic Fluid
1. Provides protection for embryo against shock, blow or pressure.
2. Embryo floats in the fluid.
3. It equalizes pressure
4. Allows fetal movement
5. Maintains constant temperature
6. Aids in effacement of cervix and dilation of uterine os.
7. Provides small amount of nutrient
The Fetal Membrane:
It has two layers
Chorion– It is thick opaque membrane derived from trophoblast.
Amnion – It is inner layer, it is smooth, tough, translucent membrane derived
from inner cell mass.
Changes by weeks of gestational age
Germinal period (0~3 Weeks)
1st week
- Cleavage division
- formation of morula& blastocyst
- Implantation of Blastocyst
2nd
week
- Implantation is complete
- Formation of biliminar embryonic disc.
- Amniotic cavity
- Amnion
- Yolk sac
- Connecting stalk
- Chorionic sac
3rd
week
- formation of trilaminar germ disc.
- Primitive streak.
- Notochord.
Gastrulation
This is a process by which bilaminar germ disc is converted into trilaminar
embryonic disc.
Primitive streak appears at the 15th day. It is narrow median groove formed by
ectodermal cell.
A neural groove (future spinal cord forms over the notochord with brain bulge
at one end).
Somites, the division of future vertebra forms. It is formed by proliferation of
mesoderm into paired cuboidal bodies called somites.
Primitive heart tube is forming. Vasculature begins to develop
Embryonic Period (4th
-8th
week)
week -4
• Three Germ layer appears.
• Folding of the embryo (Begins to curve into C- shape).
• Heart further develops.
• Brachial arches, grooves will form.
• Neural tube closes.
• Ear begins to form as otic pit.
• Arm buds and tails are visible.
• Pulmonary primordium appears.
• Hepatic plate appears.
• Cystic diverticulum, which will become gall bladder and pancreatic bud will
appear.
• Urorectal septum begins to form.
• Anterior and posterior horn differentiate into spinal cord.
• Spleen appears.
• Uretric buds appears.
Week-5
Embryo measures 8 mm in length.
Lens pits and optic cups form.
Nasal pit forms.
The brain develops.
First heart beat begins and four chambers are functioning.
Leg buds form and hands form as flat paddles on the arms.
Umbilical cord develops
Week-6
Embryo measures 13-mm.
Lungs begins to form
Arms and legs have lengthened.
Hands and feet have digits.
Gonadal ridge begins to perceptible.
Lymphatic system begins to develop.
Nostrils forms.
Intestine and pancreas grow
Week-7
Embryo measures 18 mm.
Nipples & hair follicles begin to form.
Location of elbow & toes are visible.
Teeth begin to develop.
All essential organs have at least begun formation.
Week-8
Cartilage & bones begins to form.
The tongue begins to develop.
Intestine moves out of the umbilical cord in to the abdomen.
Facial features continue to develop.
Sex differentiation begins.
Embryo measures 30 mm and weight is 1 gm.
Fetal period
The fetal period is extending from the beginning of the third month(9th
week)
up to the termination of pregnancy.
Associated with complete development of placenta, umbilical cord & fetal
membranes.
Developing organism is called fetus.
Week-9
Fetus is about 50 mm long and weight is 8 gms.
Head constitutes half the crown heel length of fetus.
Face is broad, eyes get widely separated, ears are low set and eye lids gets
fused.
Movement begins.
Most of the joints are formed.
Week 10
Face has human profile.
Placenta begins to function.
Genitalia have male or female characterstics but still not fully formed.
Week 11
Genitals appear well differentiated.
Hair and nails begins to grow.
Fingers and toes are separated.
Amniotic fluid begins to accumulate as the kidneys begins to function.
Week-12
Length is about 8 cm and weight is 25 gms.
Eyes are widely spaced.
Vocal cords begin to form.
Heart beat is audible by droppler.
Pancreas is active.
RBCs are produced in liver.
Week-13
Growth is rapid.
Inhaling and exhaling have started.
Neck is getting longer and hands becoming more functional.
Week-14
Fetal skin is almost transparent.
More muscle tissues and bones have developed.
Thyroid gland has matured and fetus begins to produce hormones in boys
prostate gland and in females the ovaries move from abdomen to pelvis.
Fine hair called lanugo develops.
Week-15-16
Sucking motions are made by mouth.
Fetus makes active movements.
Tiny bones in the middle ear begin to harden.
Ovaries are differentiated and contain primary ovarian follicles.
Meconium is made in intestinal tract.
Liver and pancreas are functioning.
By end of 16th week sucking, swallowing and blinking are evident.
Week 17-20
Lanugo covers the entire body.
Eyebrows & eyelashes appear.
Mother feels fetal movements, known as quickening.
Nails appear on fingers & toes.
Skin is covered with vernixcaseosa.
Brown fat is formed & is site of heat production.
By 18th
week, uterus is formed & canalization has begun.
By 20th
week testes begins to descend.
Fetal heart beat can be heard with stethoscope.
Immunities are transferred from mother to fetus.
Week 21-25
21 Week
Shows substantial gain in weight.
Rapid eye movement begins.
WBCs are under production.
More amniotic fluid is swallowed.
22 Week
Eye lids & eye brows are fully formed.
Liver breaks down bilirubin.
23 Week
Proportion of body is quite similar to a new born.
Fetus is able to hear.
24 eek
Baby is officially considered viable.
By end of this week fetus has grown 28-36 cm & weighs 550 gms.
Pupils react to light.
Taste buds begin to form.
Production of lung surfactant begins.
25 Week
Structure of spine begins to form the joints, ligaments and rings.
Blood vessels of lungs develop.
Nostrils begin to open.
Week 26-29
26 Week
Fetus touches to a length of about 35-38cm & weighs about 1200gms
Brain develops rapidly.
Retina begins to form.
Air sacs in lungs forms now.
Eye lids open in 26th week
27 Week
Response to sound grows.
The central nervous system matures.
Lungs continue to grow & are ready to function outside of the womb.
Retina has formed.
28 eek
Eyelids open & close.
Fetal body is getting plump & rounded.
Muscle tone is improving.
29 Week
Fetal head is in proportion with body now.
Fat accumulate under the skin.
Movement is increased.
Fetal spleen is important site of hematopoiesis.
Male testes descend inscortum& female clitoris is prominent.
Week 30-34
Length is about 38-43 cm weight is about 1,600 gms.
As fetus continues to grow the amniotic fluid will decrease.
Early lanugo disappears slowly & owns hair may begin to appear.
Bone marrow produces RBCs.
30 Week
Physical growth slows down.
Fetus gains weight.
Bones are fully developed, but are still soft and pliable.
31 Week
Movements are bit reduced because of increased size.
All five senses are working as thalamic brain connections which mediate
sensory input form.
32 Week
Active mores reflex is present.
The skull is quite pliable & not completely joined.
33 Week
In male fetus the testicles descend into the scortum.
Eyes are opened wide when awake & closed while sleeping.
Fetus has already turned to a head down position.
Week 35-40
Fetus reaches a length of about 40-46 cm & weight is around 1,800-1,900
gms.
Lanugo disappears.
Fetus takes up the space in most of uterus & mother may feel like chut has run
out of room.
36 Week
Fetus reaches a length of about 40-46 cm & weight is around 1,800-1,900
gms.
Lanugo disappears.
Fetus takes up the space in most of uterus & mother may feel like chut has run
out of room.
37 Week
Fetus is official full term.
Length reaches up to 42-48 cm & may weigh 1,800-2,700 gms.
Grasp reflex is firmly established.
38 Week
Birth position is usually assumed.
Fetal intestines are accumulating lots meconium.
Hairs are thick.
Circumference of head & abdomen are about same size.
39 Week
Lanugo has gone except on the upper arm & shoulders.
Lungs are matured and surfactant production is increased.
Fat stores are more that will help to regulate the body temperature after birth.
Fetus is around 50 cm in length & weighs about 3288 gms.
40 Week
Much of vernixhas disappeared.
15 % of baby's body is fat.
Breast buds are present.
Lungs will continue to develop until birth.
Fetus is 51cm &weight is around 3400 grams.
Any time & any day the fetus is delivered now and the development continues
postnatal with child development stages.
Pregnancy at Risk: Conditions That Complicate Pregnancy
Learning Objectives
At the end of this chapter, the student should be able to:
1. Compare and contrast the pathophysiology of the three major classifications
of diabetes in the pregnant woman.
2. Explain treatment goals for the pregnant woman with diabetes.
3. Differentiate between the care of the pregnant woman with pregestational
diabetes and one with gestational diabetes.
4. Describe typical nursing concerns for the pregnant woman with diabetes.
5. Differentiate between pregnancy concerns for the woman with iron-deficiency
anemia and one with sickle cell anemia.
6. Compare and contrast placenta previa and abruptio placentae according to
characteristics of bleeding and other clinical manifestations.
7. Apply the nursing process to the care of a pregnant woman with a bleeding
disorder.
8. Differentiate four categories of hypertensive disorders in pregnancy.
9. Discuss treatment and nursing interventions for the woman with
preeclampsia-eclampsia.
10. Contrast the management of a multiple gestation pregnancy with that of a
singleton gestation.
Prenatal care
Pre-natal care includes:
1. Medical & nursing care
2. Taking history
3. Physical exam.
4. Obstetrical exam.
5. Nutrition during pregnancy
6. General hygiene during pregnancy
7. Minor discomforts during pregnancy
8. Preparation for labor & delivery
Importantof Antenatal care
1. Maintaining mother in best possible health condition.
2. Detecting complications earlier.
3. Maternal education: for diet, general health,vaccination, psychological
support.
The first visit called booking. This includes the followings