Topic 2 Flashcards
teratogen
any agent that can cause a birth defect or negatively alter cognitive or behavioral outcomes of the individual
- severity/damage is greatly influence by dose, genetic susceptibility, maternal state, and time of exposure
- difficult to identify due to numbers and defects occurring later in life
General results of exposure to teratogens
- initial growth spurt=greatest susceptibility. Eyes and CNS vulnerable throughout pregnancy
- embryonic period: major structural abnormalities
- fetal period: minor abnormalities and functional defects like stunted growth/problems with organ functioning
types of teratogens
- nonpsychotropic drugs
- infectious maternal disease
- chronic medical conditions
- psycotropic drugs
Rubella
- contagious, similar to measles
- pink rash, swollen lymph nodes, mild fever
- vaccination is a live attenuated virus: not for months -1 to 9 of pregnancy
- congenital damage in first trimester: death, deafness, growth retardation, cataracts, glaucoma, cognitive deficits, etc. (eyes are very susceptible)
Tetnus
vaccination is not a live virus-therefore safe during pregnancy.
Varicella
- chickenpox
- live virus vaccine
- congenital varicella syndrome similar to regular varicella
Toxoplasmosis
3 ways of transition of parasite toxoplasma gondii
- cat litter/fetus ( cat is primary host)
- food-uncooked infected meat
- congenital: if mother consumes uncooked infected meat
- -mental retardation, abnormal motor abilities, visual impairment
Pregnancy and diet
- raw fish (harmful bacteria)
- swordfish (mercury levels). fetus: developmental delays, brain damage
- deli meats (listeria). fetus: blood poisoning, infection
- hot dogs (listeria)
- soft cheese (listeria)
- unpasteurized honey
- raw meat (coliform bacteria, toxoplasmosis and salmonella)
What is the most common teratogen?
ALCOHOL
Why does having diabetes classify a pregnancy as high-risk?
Because the metabolic condition of the fetus has been compromised. It is hard to regulate insulin levels and blood sugar levels. If fetus environment fluctuates then motor development will be affected.
Diabetes Mellitus
fetal hyperinsulinemia may result in
- macrosomia (birth weight above 90th percentile for gestational age)
- inhibition of maturation of lung surfactant
- muscle weakness/cardiac arrhythmias
- permanent neurological damage
Macrosomnia
- linked to obesity later in life
- CNS deformities
- congenital anomalies (heart defects)
- musculoskeletal deformities
- respiratory distress syndrome
- traumatic birth injury
Dependency Ratios
# of individuals likely to be "economically dependent" on the support of others -determined by age structure and provides an indication of the social support structures required for population
Youth Dependency Ratio
Elderly Dependency ratio
Total Dependency ratio
- ratio of youth (0-14) per 100 of working age (15-64)
- ratio of elderly (65+) per 100 of working age
- ratio of youth+elderly per 100 working age
Where is investment needed if dependency ratios are high?
total:if high, working class and economy face a support burden
youth-education, early childcare
elderly-pension, healthcare
fertility rate
avg no of children that would be born if all women lived to the end of their childbearing years and bore children according to the given rate
Replacement rate
how many children are needed to replace a country’s population
Replacement Fertility Rates
no mortality in childbearing years:
-developed countries: 2.1
less developed countries: 2.5-3.3
(0.1 and 0.5 buffers are for death, those who choose not to/cannot have children, and increased male vs female births)
Replacement Fertility Rate trends
if 2.1, growth=0
if 2.1, growth increases and median age decreases
Birth rate
avg. annual no of births per 1000 persons
-determines rate of population growth
depends of level of fertility and structure of population
does not factor in migration
death rate
avg annual no. of deaths per 1000 persons
-indicates current mortality impact on population’s growth
giving birth over 35
increased likelihood:
- pre-existing hypertension
- pre-eclampsia
- gestational diabetes
- placenta previa
- Caesarian section
- young-for-date infant
- small-for-gestational age infant
- chromosomal/congenital abnormality
Pre-eclampsia
pregnancy induced hypertension
cure=giving birth
Gestational Diabetes
high risk population: aboriginal
- pregnancy induced
- difficult to regulate (fluctuating environment is bad for fetus)
- mother+child increased factor to develop type 2 diabetes later
Placenta Previa
when the placenta is covering the vaginal canal causing it to come out first-usually causes death of child
gestational age
conceptional age
-40 weeks-from day 1 of last mentrual cycle to birth of infant (ovulation assumed to take place 2 weeks later)
-38 weeks-from time of fertilization to birth
full term=2weeks before to 2 weeks after
3 Periods of pregnancy
- Germinal (0-2 wks)
- problems result in miscarriage - Embryonic (2-8)
- most critical for development (organs) - Fetal (8-40)
Germinal
-At conception, a one-cell zygote is created (fertilized egg). Cell division begins.
By day 3, becomes a blastocyst.
-Blastocyst enters uterus and attaches to uterine wall
(implantation into endometrium).
*Chemicals signify the presence of the blastocyst so mother’s body does not attack as a foreign body.
Embryonic
begins as blastocyst attaches to uterine wall (becomes embryo)
~1in by 8th week
4 weeks
structures that form the face and neck are becoming evident. heart and blood vessels continue to develop. lungs, stomach, and liver start to develop.home pregnancy test is now positive
5 weeks
The plate that will become the heart has developed. The foundations for the brain, spinal column and nervous system has been established. skeleton is also forming. The embryo has a distinct organization that has a top, bottom, left, right, front and back.
6 weeks
Facial features are visible, including a mouth and tongue. The eyes have a retina and lens. The digestive system starts forming, starting with the first cells of the stomach and the intestine. There are small indentations in the head, ready for the development of facial features, eyes, and ears. The outline of the jaw starts to form.
8 weeks
Eyelid folds are forming. The baby’s eyes are still very wide apart on the sides of the head, but will eventually center The tip of the nose is present. On an ultrasound you can see that the aortic and pulmonary valves of the heart. The tubes that lead from the throat to lungs are branching and the torso is getting longer and beginning to straighten out. -definite elbows, arms, toes, fingers.The baby is protected by the amnionic sac, filled with fluid. Inside, the child swims and moves.
Myogenic Movement
- possible at end of embryonic period
- occur through local stimulation of individual muscles with no nervous/external stimulation
- striated muscles are innervated with alpha motorneurons
Fetal Period
Period of rapid growth in size and further cell differentiation, leading to functional capacity
- greatest growth rate from 8-16 weeks
- greatest weight increase last month
hyperplasia
hypertrophy
- increase in no of cells
- increase in size of individual cell
ultrasound
- determine due date
- confirm fetal viability
- determine location
- confirm location of placenta
- No. of fetuses
- major physical abnormalities
- asses growth
- check for movement/heartbeat
- determine sex
Neurogenic Movements
- appear at 20 weeks (conceptional)
- generated by CNS when myelination begins (16-20 weeks)
1. completed when child is 4
2. influences neural conduction and motor capabilities
Importance of movement in Utero
- facilitates development of neural pathways
- ensures there are no adhesions in skin
- shapes skeletal system by producing mechanical influences on the bones and joints
- essential for post-natal movements
Arthrogryposis
joint contractures that develop prenatally and appear at birth due to limited mobility
causes: insufficient room, atrophic muscles, malformed CNS and spinal chord, abnormally developed bones, joints, or joint linings
exercise and pregnacy
-no evidence that moderate to low intensity will result in adverse effects
Importance:
-lowers risk of gestational diabetes and pre-eclampsia
-helps with excessive gestational weight gain
Low birth weight (small-for-date)
less than 5.5lbs
very low less than 3.3lbs
-mostly occurs in young and old mothers
-means infant has experience intrauterine growth retardation
Causes of Low Birth weight
diet, drugs, smoking, infections, disease, social class, multiple births
-50% of very low birth weight infants develop developmental delay or disability
Young -for-Date (pre-term)
expected birth weight for gestational age before 37 weeks
-infant mortality has decreased due to neonatal care, but incidence of preterm birth is increasing
Causes of preterm infants
drugs, smoking, maternal age, weight gain, history of miscarriage, adverse social/economic conditions, peridontal disease
-developmental delay and disability in motor skill
