Lecture 7.1: Foetal Growth & Development Flashcards
1
Q
What is the average length of pregnancy/gestation?
A
40 weeks
2
Q
How is pregnancy counted?
A
- From the first day of the woman’s last period
- Not the date of conception which generally occurs two
weeks later
3
Q
EDD by LMP is calculated by…?
A
Adding 280 days (40 weeks) to the first day of the last menstrual period
4
Q
What is Gestational Age?
A
It is the age of the pregnancy from the last normal menstrual period (LMP)
5
Q
What is Foetal Age?
A
It is the actual age of the growing baby
6
Q
What is Crown-Rump Length (CRL)?
A
It is the measurement of the length of human embryos and foetuses from the top of the head (crown) to the bottom of the buttocks (rump)
7
Q
When is CRL measured? Why is it done?
A
- 7 & 13 weeks
- To date the pregnancy & estimate EDD
- Rule out ectopic
- Confirm number of foetuses
8
Q
When does Foetal Period start?
A
- From week 10 of gestation (week 8 of foetal
development)
9
Q
What happens during the Foetal Period? (5)
A
- All the systems have formed during the embryonic
stage and continue their development during the fetal
stage - Increase in size of baby
- Increase in protein mass at first and then adipose
tissue - There are significant changes at birth.
- Even at birth the body systems have not yet completed
their development
10
Q
At birth what is the the average weight, head circumference & length of a baby boy?
A
- Weight of 3.5kg
- Head circumstance of 35cm
- Length of 52 cm
11
Q
What weeks is the Germinal Period?
A
0 to 2 weeks
12
Q
What weeks is the Embryonic Period?
A
2-8 week after fertilisation
13
Q
What weeks is the Foetus Period?
A
8 weeks to birth
14
Q
What weeks is the Neonatal Period?
A
Birth to 4 weeks
15
Q
What is a Preterm Neonate?
A
<37 weeks
16
Q
What is a Very Preterm Neonate?
A
28 to 32 weeks
17
Q
What is an Extremely Preterm Neonate?
A
Less than 28 weeks
18
Q
What is the Neonatal Period?
A
Birth to 1 month
19
Q
What is the Infancy Period?
A
1 month to 2 years
20
Q
What is the Childhood Period?
A
2 years to puberty
21
Q
What is the Puberty Period?
A
12 years to mid-teens
22
Q
What is the Young Adult Period?
A
Late teens to early twenties
23
Q
What is Very Low Birth Weight?
A
1500 grams
24
Q
What is Low Birth Weight?
A
<2500 grams
25
What is Macrosomia?
* Excessive birth weight
* >4500g
26
What should be supplemented in the Pre-Natal/Ante-Natal Period?
* Vitamin D supplementation
* Folic acid
27
What should be avoided in the Pre-Natal/Ante-Natal Period? (4)
* Listeriosis: Drink only pasteurised or UHT milk
* Do not eat ripened soft cheese
* Do not eat pâté
* Do not eat uncooked or undercooked ready-prepared
meals/eggs
28
How is Pregnancy split up?
Pregnancy is also divided into three 13 week trimesters
29
What happens to the mother in the 1st Trimester?
Rapid influx of hormones causes intense pregnancy symptoms
30
What happens to the mother in the 2nd Trimester?
* Most symptoms stop
* Pregnancy starts to show
31
What happens to the mother in the 3rd Trimester?
Extra weight makes it hard to sleep and move
32
What Trimester can the baby's heartbeat first be heard?
1st trimester
33
What is the baby's size and weight at the end of the 1st Trimester?
* 2.9"
* 0.8oz/22g
34
When can the baby's gender be revealed?
* 2nd Trimester
* 18-20 weeks
35
What is the baby's size and weight at the end of the 2nd Trimester?
* 14"
* 1.7lbs/771g
36
What is the baby's size and weight at the end of the 3rd Trimester?
* 20.3"
* 8.1lbs/3600g
37
Down syndrome risk at maternal age 20 years
1:1528
38
Down syndrome risk at maternal age 44 years
1:37
39
Down syndrome risk at maternal age 50 years
1:6
40
What is Nuchal Translucency (NT)?
It is the sonographic appearance of a collection of fluid under the skin behind the foetal neck in the first trimester of pregnancy
41
What is Nuchal Fold Thickness?
It is similar to Nuchal Translucency, but refers to the measurement in second trimester
42
Why are Nuchal Translucency & Nuchal Fold Thickness important?
Detect chromosomal abnormalities
43
What is the "Combined Test"? What does it test for?
* Nuchal translucency (NT)
* Beta-human chorionic gonadotrophin
* Pregnancy associated plasma protein- A
* Screens for Down’s, Edwards' & Patau's between 11-14
weeks
44
What is the “Quadruple Test”? What does it test for?
* Alpha-fetoprotein (AFP)
* Total human chorionic gonadotrophin (hCG)
* Unconjugated oestriol (uE3)
* Inhibin-A
* Only screens for Downs
45
Why may the baby not growing as much as expected? (4)
* Normal small baby
* Pathology in baby
* Placental problems
* Maternal Health (only in extreme maternal ill health)
46
What is the Bi-Parietal Diameter (BPD)?
The distance between the parietal bones of the foetal skull
47
What is the Bi-Parietal Diameter (BPD) used in combination with to assess growth in Trimesters 2 & 3?
* Abdominal Circumference
* Femur Length
48
Why can Macrosomia be harmful?
Difficult birth
Post natal hypoglycaemia
Surfactant deficiency
49
Why can Macrosomia occur? (3)
* Foetal Hyper-insulinism, e.g. infant of mother with
diabetes
* Overweight mother
* Beckwith-Wiedemann Syndrome
50
What is the Barker Hypothesis?
* Advocates that the origins of chronic diseases of adult
life lie in foetal responses to the intrauterine
environment
* Specifically, it suggests that the genesis of adult-onset
chronic diseases originates through foetal adaptations
to undernourishment
51
When does Respiratory System development begin?
Week 4
52
When does Cardiovascular System development begin?
Week 3
53
By what day is heart pumping blood?
Day 21-22
54
When does Urinary System development begin?
Week 4
55
What week does foetal kidney function begins?
Week 10
56
What is Oligohydramnios?
When you have too little amniotic fluid
57
What is Potter's Sequence? What conditions can cause it?
* Describes the typical physical appearance caused by
pressure in utero due to oligohydramnios
58
Why can Potter's Sequence or Oligohydramnios occur? (6)
* Infantile polycystic kidney disease
* Renal hypoplasia
* Obstructive uropathy
* Foetal renal failure
* Placental insufficiency
* Preterm pre-labour rupture of membranes
59
How often is amniotic fluid “turned over”?
Every 3hrs
60
Amniotic fluid volume is .....ml at 38 weeks
1000
61
Amniotic fluid volume reduces to ....ml at 42 weeks
500
62
In early pregnancy what is amniotic fluid formed from?
Formed from maternal blood and from foetal extracellular fluid by diffusion across non-keratinised skin
63
In later pregnancy what is amniotic fluid formed from?
Fluid is produced by the renal tract and urine makes up a significant portion of amniotic fluid, the foetus then swallows amniotic fluid
64
What is Polyhydramnios?
Too much amniotic fluid around the baby during pregnancy
65
Why can Polyhydramnios occur?
Inability to swallow amniotic fluid such as in oesophageal atresia and anencephaly
66
How can amniotic fluid volume be measures?
Ultrasound
67
What embryonic layer is the nervous system derived from?
Ectoderm
68
When does Nervous System begin development?
Week 3
69
Myelination (by the Schwann cells) of brain begins in what month?
Month 4
70
Is myelination complete at birth?
Myelination is NOT complete at birth e.g. corticospinal tract is not fully myelinated
71
At birth most of the neonate’s movements are
72
At birth most of the neonate’s movements are...?
Spinal reflexes
73
With myelination of the corticospinal tracts the “higher” centres over-ride these spinal reflexes and voluntary movements develop by....of life
1st year
74
What happens if corticospinal tracts are damaged?
Persistence of spinal reflexes leading to the features of cerebral palsy and in a stroke
75
When can foetus begin moving?
Week 6
76
Maternal awareness of foetal movements from .... weeks onwards
17
77
What is Meconium?
* Meconium is a newborn's first poop
* This sticky, thick, dark green poop is made up of cells,
protein, fats, and intestinal secretions, like bile
78
Why can Meconium occur in-utero? How does it present?
* This can happen when babies are "under stress" due
to a decrease in blood and oxygen supply
* Green amniotic fluid when waters break
79
What are the 2 Types of Intrauterine Growth Restriction (IUGR)?
Asymmetrical and Symmetrical
80
What is Asymmetrical IUGR? What percentage of IUGRs does it represent?
* The baby's head and brain are the expected size, but
the rest of the baby's body is small (abdominal
circumference small)
* 70%
81
What is Symmetrical IUGR? What percentage of IUGRs does it represent?
* All parts of the baby's body are similarly small in size
* 30%
82
What 2 circumferences are used to consider IUGR?
Abdominal
Head
83
What 2 circumferences are used to consider IUGR?
* Abdominal
* Head
84
What conditions can cause Asymmetrical IUGR?
Usually due to maternal systemic disease (e.g., hypertension) that results in placental insufficiency
85
What conditions can cause Symmetrical IUGR? (3)
* Genetic Disorder (e.g., aneuploidy)
* Congenital Heart Disease
* Early intrauterine TORCH infection that affects the
foetus early in gestation
86
What is Primary Ciliary Dyskinesia?
Caused by genetic mutations that affect the tiny hairline cilia in the lungs, nose and ears, impairing their ability to remove germs and pollutants, and allowing mucus buildup and infection
87
What is Placenta Accreta?
Serious pregnancy condition that occurs when the placenta grows too deeply into the uterine wall, can lead to haemorrhage after birth
88
What is Placenta Increta?
The placenta attaches itself even more deeply into the muscle wall of the uterus
89
What is Placenta Percreta?
The placenta attaches itself and grows through the uterus, sometimes extending to nearby organs, such as the bladder
