Prenatal development and birth Flashcards
What is gestation?
38 week period between conception and birth
What is gestational age?
Age of unborn baby, usually dated from first day of last menstrual cycle
What are the four stages of prenatal development?
Conception, germinal, embryonic, foetal
Where does conception occur?
Fallopian tube - creates zygote
What happens in germinal stage?
blastocyst implants in uterus wall [0-2 weeks]
What happens in embryonic stage?
umbilical cord connects embryo to placenta, amniotic sac [3-8 weeks]
What happens in foetal stage
[8 weeks to birth]
organs and body become complex
toenails and eyelids
appearance of bone
What is monozygotic birth
one egg - one sperm
identical twins
share 100% of genes
What is dizygotic birth
Two eggs - two sperm
more common
share 50% of genes, like non-twin siblings
What are risk factors in prenatal development
Mother’s biological characteristics
Exposure to teratogens
When are critical periods in prenatal development
especially early for major impact
Timing intensity and duration all have impact
What are prenatal hazards [teratogens]
medicinal drugs
nonmedicinal drugs [foetal alcohol syndrome, foetal alcohol effect]
maternal disease
environmental hazards
What are risks of being over 35?
higher risk of infertility, downs syndrome
What are risks of being teenage mother?
higher risk for low birth rate [mother and child still growing, competing for nutrients’, stillbirth, birht complications
What are paternal factors that impact on sperm / prenatal development?
alcohol
marijuana, tobacco
pesticides
age
What is impact of pre-birth stress
higher rate of spontaneous abortion, low birth weight etc
What is labour?
uterine contractions that affect dilation of cervix and force fetus through birth canal
What are the three foetal presentations?
cephalic [head down - normal]
breech
transverse
What are stages of labour
first stage - cervix dilation to 10cm
transition - full dilation
second stage - head moves into birth canal, culminates in birth
third stage - expulsion of placenta and umbilical cord
What is Lamaze method?
breathing, birth is shared emotional process
What is Read method?
feeling of pain indicates fear, train in stress reduction
What is Leboyer method?
babies born into low light, less stressful environments
What are the three problems in labour?
Faulty power - uterus doesn’t contract
Faulty passageway - placenta previa, blocking cervix
Faulty passenger - baby presenting strarngely
