1. GROWTH AND DEVELOPMENT
OF PRENATAL PERIOD
SHINU K ANTONY
Ist YEAR MSc NURSING
GOVT COLLEGE OF NURSING
ALAPPUZHA
2. PERIODS IN PRENATAL
DEVELOPMENT
• Ovular period or germinal period: This
lasts for first 2 weeks following ovulation.
• Embryonic period: Begins at 3rd week
following ovulation and extends upto 10
weeks of gestation
• Fetal period: Begins after 8th week
following conception and ends in delivery
3. GAMETOGENESIS
Gametogenesis is a biological
process by which diploid or haploid
precursor cells undergo cell division
and differentiation to form mature
haploid gametes
13. •Days 14-21 post conception: notochord
develops, ectoderm thickens to form neural plate
and neural folds.
•Days 21-28 post conception: neural folds fuses
to form neural tube. Four primitive cardiac
chambers. First heart beat on day 21.
•Weeks 4-6 post conception: optic vesicles
appear, complete neural tube closure (D30). Limb
buds appear. Formation of face.
•Weeks 8-12 post conception: external genetalia
develop
14. PRINCIPLE EVENTS…………….
•Weeks 20: skin is covered with lanugo. Vernix
caeosa is present.
•Weeks 28: testes descend to the internal
inguinal ring
•Weeks 36: one testicle usually descends into the
scrotum. Lanugo tends to disappear.
•Weeks 40: both the testicles descend into the
scrotum. Nails project beyond the finger tips.
Posterior fontanelle is closed.
15.
16. Nutrition: Three stages of fetal nutrition
•Absorption
•Histotrophic transfer
•Hematotrophic
Fetal blood:
• Haematopoiesis first in yolk sac by 14th day.
•10th week the liver becomes the major site.
Leucocyte: Leukocytes appear after 2 month of
gestation
Urinary system :
• the end of first trimester- nephrons are active
•near term the urine production rises to 650ml per
day.
17. skin :
• At 16th week, lanugo
•Sebaceous glands at 20th week and and the sweat
glands later.
Gastrointestinal tract:
•As early as 10-12week, the fetus swallows amniotic
fluid.
•The meconium appears from 20th week.
Respiratory system:
• At 28th week, alveoli expand and are lined by cuboidal
epithelium.
•At the end of 24th week lung surfactant
Fetal endocrinology: Growth
hormone, ACTH, prolactin, TSH and gonadotropin
hormones are produced by fetal pituitary as early as the
10th week.
19. Systemic supervision (examination and
advice) of a women during pregnancy is
called antenatal / prenatal care.
It comprises of
•Careful history taking and examination
(general and obstetrics)
•Advice given to the pregnant women
20. AIMS
•To screen the high risk cases
•To prevent or detect and treat at the earliest any
complications
•To ensure continued medical surveillance and
prophylaxis
•To educate the about the physiology of pregnancy and
labour by demonstrations, charts and diagrams
•To discuss with the couple the place, time, mode and
the delivery, provisionally and the care of new born
•To motivate to the couple the need of family planning
and also appropriate advice to the couple seeking MTP
21. The objective is to ensure a normal
pregnancy with delivery of a healthy
baby from a healthy mother.
22. PROCEDURES AT FIRST VISIT
HISTORY COLLECTION
PHYSICAL EXAMINATION
General examination
Obstetrical examination
investigations
23. PROCEDURE AT SUBSEQUENT VISIT
Objective
To assess fetal well being
Lie, presentation, position and number of fetus
Anemia, preeclampsia, amniotic fluid volume and
fetal growth
To organize specialist antenatal clinics for
patients with problem like cardiac disease and
diabetics.
To select time for USG, amniocentesis or CVS
when indicated.
24.
25. AIMS OF ANTENATAL FETAL
MONITORING
•To ensure satisfactory growth and well being of
the fetus throughout pregnancy
•To screen out the high risk factors that affect the
growth of the fetus
26. INDICATIONS OF ANTEPARTUM FETAL
MONITORING
•Pregnancy with obstetric complications
•Pregnancy with medical complications
•Others like advanced maternal age, previous still
birth, birth of a baby with structural abnormality
etc
•Routine antenatal testing
27. NONINVASIVE PRENATAL TESTS
•Fetal ultrasonography
•Fetal echocardiogram
•Computerized Tomography and MR imaging
•MS-AFP and triple test
•Fetal Nuchal Translucency
37. HISTORY OF GENETICS
FATHER OF
GENETICS
GREGOR MENDEL
Discovered fundamental
law of genetics
In 1853 Mendel
conducted his
experiments on garden
peas (Pisum
sativum).
38. CHROMOSO
MES
In human body
23 pairs of
chromosomes
are there. Out
of these 22 are
autosomes
and one pair
sex
chromosomes
46. GENETIC TESTING
Genetic testing refers to the analysis of a
person’s DNA, chromosomes, proteins or
certain metabolites obtained from a sample
of blood or other body tissue in order to
detect changes that indicate the presence
or absence of a genetic condition or a pre
disposition to develop one.
[JOYCE M
BLACK, 2010]
Genetic screening is presumptive
identification of an unrecognized genetic
predisposition for a future disease in
individual or their progency for which
preventive or disease course altering
interventions exist.
47. PURPOSES OF GENETIC TESTING
To confirm a present condition.
To determine whether an
individual is a carrier of a genetic
condition.
To detect fetal abnormalities.
To predict diseases in
asymptomatic individual
48. INDICATIONS
One or more birth defects
A genetic disorder
A chromosome abnormality
Intellectual development disorder or developmental delay
Neuromuscular abnormalities
Unexplained metabolic problems
Congenital or familial hearing loss of blindness
Abnormal sexual development
Prenatal exposure to drugs or medications including alcohol
Cancer
56. MOLECULAR GENETIC TESTS
I. AMPLIFICATION
POLYMERASE CHAIN REACTION
CLONING DNA IN BACTERIA
II. SEPERATION AND DETECTION
CELL CULTURES
III. DNA ISOLATION
59. ASSESSMENT OF FETAL WELLBEING
IN LATE PREGNANCY
CLINICAL
BIOCHEMICAL
BIOPHYSICAL
60. Assessment of fetal lung maturity
•Estimation of lecithin:sphingomyelin ratio
•Shake’s test or bubbles test or Clement’s
•Foam stability index
•Thin layered chromatography
•Measurement of saturated phosphatidyl
choline
•Fluorescence polarization
•Amniotic fluid optical density
•Lamellar body count
•Orange colored cells
•Amniotic fluid turbidity
61. ASSESSMENT OF SEVERITY OF RH-
ISOIMMUNIZATION
It is done by amniocentesis for
estimation of bilirubinin the amniotic fluid
by spectrometric analysis. The optical
density difference at 450nm gives the
prediction of the severity of fetal
hemolysis
62. BIOPHYSICAL PROFILE
I.FETAL MOVEMENT COUNT
1. Fetal movement count 10 formula
2. Daily fetal movement count (DFMC)
3. Doppler imaging
II.VAS
III.NONSTRESS TEST
iv.BIOPHYSICA L PROFILE
v.MODIFIED BPP
63. parameters Minimal normal criteria score
Non stress test(NST)
Fetal breathing
movements
Gross body
movement
Fetal muscle tone
Amniotic fluid
Reactive pattern
One episode lasting >30sec
3discrete body or limb
movements
1 episode of extension (limb
or trunk) with return of
flexion
1 pocket measuring 2cm in
two perpendicular planes
2
2
2
2
2
64. BPP score Interpretation management
8-10
6
4
0-2
No fetal asphyxia
Chronic asphyxia
Chronic asphyxia
Certain asphyxia
Repeat testing at
weekly interval
If >36wk deliver
If >=36wk deliver, if
<32wk repeat testing
in 4-6hrs
Test for 120mts,
persistent score <=4
deliver regardless of
gestational age
67. Maternal factor Fetal / infant risks
Adolescent age,
pregnancy that
occurs at the two
age extremes
<16yrs and
35yrs.
Advanced
maternal age
issues
Small maternal
size
Large maternal
size
Nutrition
Prenatal care
Support system
Socioeconomic system
Preeclampsia
IUGR
LBW
Chronic diseases that affect pregnancy
Increased incidence of chromosomal abnormalities
Pregnancy related conditions might occur eg. Diabetes,
preeclampsia,vaginal bleeding
Increased risk of congenital or chromosomal abnormalities
IUGR
Increased potential for hypoxia during labor and delivery
Increased risk for poor fetal nutrition
70. PATTERNS OF INHERITANCE
I. AUTOSOMAL
DOMINANT
INHERITANCE
VERTICAL PATTERN OF
INHERIANCE
MALES AND FEMALES
ARE EQUALLY
AFFECTED.
50% OF CHANCE OF
INHERITNG NORMAL
GENE AND 50% OF
MUTATED GENE
71. PATTERNS OF INHERITANCE
II. AUTOSOMAL RECESSIVE
INHERITANCE
HORIZONTAL PATTERN OF
INHERITANCE.
RELATIVES OF SINGLE GENERATION
TEND TO HAVE THE CONDITION.
WHEN CARRIERS HAVE CHILDREN
TOGETHER,25% CHANCE OF
INHERITING MUTATED GENE.
72. III. X LINKED DOMINANT INHERITANCE
The sons of a man with an X-linked
dominant disorder will not be affected,
but all of his daughters will inherit the
condition.
A woman with an X-linked dominant
disorder has a 50 percent chance of
having an affected daughter or son with
each pregnancy.
73. PATTERNS OF INHERITANCE
IV. X LINKED RECESSIVE
INHERITANCE
. The sons of a man will not
be affected, and his
daughters will be carrier.
a woman has a 50
percent chance of having
sons who are affected and
a 50 percent chance of
having daughters who
carry one copy of the
mutated gene.
83. GENETIC COUNSELLING
DEFINITION
Genetic counselling is the process in which patients or
their relatives at the risk of genetic disorder are made
aware of the consequences of the disorder, its
transmission ant the ways by which this can be
prevented or mitigated.
[GANGANE SD, 2008]
Genetic counselling is defined as a communication
process which deals with the human problems
associated with the occurrence or the risk of a genetic
disorder in a family
[THE AMERICAN SOCIETY OF HUMAN
GENETICS, 2008]
84. AIMS
To obtain a full history.
To establish an accurate diagnosis.
To draw the family tree.
To estimate the risk of a future pregnancy
being affected or carrying a disorder.
To give information on prognosis and
management.
To provide continued support and follow up.
To do genetic screening
85. Indications
Advanced parental age
Previous child with or family history of
Congenital abnormality
Adult onset genetic disease (pre symptomatic
testing)
Consanguinity
Teratogen exposure (occupational abuse)
Repeated pregnancy loss or infertility
Pregnancy screening abnormality
Heterozygous screening based on ethnic risk
Follow up testing
88. GENETIC COUNSELLING TEAM
The family or referring physician
The geneticist
The nurse
The other members of helping
professions.
89. INFORMATIONS CONVEYED
The specific condition or conditions
Knowledge of the diagnosis of the particular condition
Natural history of the condition
Genetic aspect of the condition and recurrence risk
Prenatal diagnosis and prevention
Therapies and referral
Support groups
Follow up
Nondirective counseling
The magnitude of the risk of occurrence or recurrence
The impact of disease on the patient and the family
Modification of disease impact and/ or risk
Anticipated future development
99. Diseases for applying gene therapy
Disease Defect Target cell
Severe combined Bone marrow cells or
immunodeficiency T-lymphocytes
Hemophilia Liver, muscle
Cystic fibrosis Lung Cells
Cancer Many cell types
Neurological diseases Parkinson’s/ Alzheimers Nerve Cells
Infectious diseases AIDS, hepatitis B White Blood Cells
100.
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Randhawa S. S. atext book of genetics. 3rd ed. India.
Vikas & company medical publishers. 2010
Terrikyle & susan carman. Essentials of paediatric nursing.
2nd edition. Newdelhi. Wolters kluwer Lippincott Williams &
wilkins. 2013
Anoop kumar tiwar. Human genome project: an
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(HJMNS). Jan-june 2012.volumeII. issue I. page numbers
22-23
World Health Organisation (WHO). Geneva. Woldheath
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