Download PRENATAL DEVELOPMENT AND BIRTH How did you develop before birth?

PRENATAL
DEVELOPMENT AND
BIRTH
How did you develop before birth?
Prenatal development
2D Ultrasound
4D Ultrasound
When can you confirm pregnancy?
• Can not be confirmed by blood or urine tests until the
zygote implants in the uterus (about 10 days after
conception).
What are the stages in prenatal development?
• Germinal - 1st 2 weeks
• Embryo – Week 3 to 8 (2 months)
• Fetus – Week 9 to birth
When is the germinal period?
Conception
• First 2 weeks
• Conception
• Zygote
• Implantation
Zygote
How does an embryo
develop?
Primitive streak
• Week 3 – 8 (2 months)
• First - “Primitive streak” develops =
neural tube = brain & spinal column
• 4th. Week
• Head takes shape
• Early heart begins to pulsate
• 5th. Week
• Arm & leg buds develop
• Webbed fingers and toes develop
• 8th. Week
• 1 inch long
• Has all basic body parts and organs (except
sex organs)
4 Weeks
8 Weeks
Do you remember?
• What needs to happen for pregnancy to be confirmed?
• About how long after conception does this occur?
• What are the three major stages in prenatal
development?
• How long is the germinal period?
• What ends this period?
• How long is the embryo when it becomes a fetus?
• At how many weeks does this happen?
When is it a fetus?
(9 weeks – Birth)
9th. Week
• 9th. Week
• Male gene triggers development of male organs
• If not, female organs develop
• Fourth, fifth, sixth months
• Heartbeat becomes stronger
• Digestive and excretory systems develop
• New neurons & synapses develop
• Up to one 500,000 brain cells per minute are
created
• Age of viability
• Can possibly survive outside the mother (with
intensive medical care)
• 22 weeks
22 weeks
Fetus (9 weeks - birth)
• Final three months
• Lungs begin to expand and contract (fetal respiration)
• Breathe using amniotic fluid as a substitute for air
• Fetus
• Grows and moves more
• Startles and kicks at a loud noise
• Becomes used to mother’s heartbeat and voice
• Teddy bear with Mother’s heart sounds story
• Responds if mother is fearful or anxious
Labor & birth
Cervical dilation chart
• Labor
• 12 hrs. – first child
• Stages of labor
10 Cm.
• 1st. = Cervical dilation
• 2nd. = Crowning
• Only about 1/3 of zygotes implant
successfully, and additional pregnancies
are lost due to miscarriage and other
factors. (Note: This varies slightly from the
lecture, but does not effect the exam.)
Crowning
What is the Apgar Scale?
• Activity
• Muscle tone
• Pulse
• Heart
• Grimace
• Reflex irritability
• Appearance
• Skin color
• Respiration
• Breathing
• Done twice – 1 & 5 minutes after birth to determine if
immediate medical care is needed
• Score = 0,1,2 for each item
• Total of 7 or above is desired
Do you remember?
• When does it become a fetus?
• When is the age of viability?
• What are the five items the Apgar test looks for?
What are some problems and solutions?
What are teratogens?
(Items increasing prenatal abnormalities)
• Types
• Substances (drugs, pollution)
• Conditions (Stress or malnutrition)
• Teratogens = Physical defects
• Cleft palate
• Thalidomide babies (deformed limbs)
Cleft palate
• Behavioral teratogens = Behavioral defects
• Hyperactivity
• Antisocial
• Learning-disabled
Thalidomide baby
• Autism
What triggers harmful teratogens?
• Timing
• Some only cause damage during critical periods
• When organ or body part is most vulnerable
• Before pregnancy
• Avoid drugs (e.g. smoking & alcohol)
• Fetal alcohol syndrome
• Better diet
• Immunizations
• Problem – Half of births are unplanned
• Threshold effect
• Some are harmless until they “cross the threshold” and become
harmful
• Alcohol, tobacco, and marijuana do more harm in combination
• This lowers the threshold for each
• Genes – May increase birth defects
• My story
What are the causes & effects of low birth
weight?
• Causes
• Born preterm
• Born small for gestational age (SGA)
• Maternal or fetal illness
• Drug use
• Every psychoactive drug
• Tobacco (Most prevalent cause)
• Malnutrition
• Effects
• Infant death
• Thinking (cognitive) problems
• Seeing and hearing problems
• In adulthood - higher rates of:
• Obesity
• Heart disease
• Diabetes
What do newborn reflexes do?
• Reflex = involuntary response to a stimulus
• Reflexes that aid survival
• Breathing – Maintains oxygen
• Shivering – Maintains temperature
• Sucking – Manages feeding
• Rooting – Searching for a nipple
• Reflexes that show the state of brain and body functions
• Babinski reflex – Toes fan upward when feet are stroked
• Stepping reflex
• Swimming reflex
• Palmer grasping reflex
• Moro reflex - Being startled
Do you remember?
• What are behavioral teratogens?
• What is an example?
• What is SGA?
• What is the most prevalent cause of it?
• What are the reflexes that aid survival?
• What five reflexes show that the brain and body are
functioning correctly?