Chapter 3 - Prenatal Development, Birth And The Newborn Flashcards
Prenatal development
The changes that transform a fertilized egg into newborn human
Prenatal development typically takes 38 weeks
Three stages of pregnancy
Zygote (1 to 2 weeks)
Embryo (3 to 8 weeks)
Fetus (9 to 38 weeks)
What occurs during the period of the zygote?
Growth and movement from fallopian tube to uterus
Within hours of conception the cells begin to divide out a rapid pace promoting growth
Blastocyst
Zygote resembles a hollow ball consisting of 100 to 200 cells
Inner layer (mass) is embryo Outer layer consists of the placenta, umbilical cord, and amino sac
Implantation
The final stage of the zygote (blastocyst burrows into the uterine wall and establishes connection with the mother’s blood vessels)
Day 7-14
Sends hormonal signals to prevent menstruation
What occurs during the period of the embryo?
Body structures and internal organs develop
Once blastocyst is fully embedded in uterine wall the embryo forms
During this rapid period of growth and specialization, embryo is highly Suspectible to environmental influences
Three layers of the embryo
Ectoderm: hair,skin, nervous system
Mesoderm: muscles, bones, and circulatory system
Endoderm: digestive system, lungs
Structure of the embryo
Placenta, amniotic sac, amniotic fluid, umbilical cord
Placenta
Organ that connects the amniotic sac to uterus
Amniotic Sac
Sac in which the embryo rests
Amniotic fluid
Cushions embryo and contains constant temperature
Umbilical cord
Houses blood vessels that join embryo to placenta
Neural tube
One end of the tube is the brain and the other is the spine
Sufficient levels of folic acid or needed to ensure neural tube closes or else Spina Bifida occurs
What occurs during the period of the fetus?
Baby becomes much larger (1 ounce to 7–8 pounds)
Bodily systems begin to work
Second trimester
Months 4 to 6
Rapid growth, refining reproductive system and Brain functions, mom can feel quickening
Third trimester
Months 6 to 9/10
Respiratory system matures, begins to practice breathing (lungs are last)
And continues to develop, fetus puts on weight
Age of viability
By 22 to 28 weeks of fetus has a chance of survival but lungs are under developed and the fetus lacks insulation layer (fat layer)
Fetal behavior
Fetus begins regular cycles of movement
Difference is an activity predict infant temperament
(More active= unhappy and difficult baby less active= happy and easy to soothe baby)
Fetal learning
Fetus is learning and already using some senses
Hearing, taste
Fetal learning- hearing
DeCasper and Spence (1986)
Pregnant moms read cat in the hat two times a day the last six weeks of pregnancy
Question: does sucking rate differ when hearing a familiar versus new story?
Results: infants sucked to hear familiar story
Fetal behavior- Taste
Mennella, Jagnow and Beauchamp (2001)
Drank carrot juice or water four times a week, for three weeks during last trimester and/or during first two months of lactation
After five months mothers begin introducing their infants to cereal prepared with water or with carrot juice
Mothers rated infants enjoyment of cereal immediately following the meal
Results: prenatal and early experience carrot juice had preference cereal flavored with carrot juice
Influences on prenatal development- Maternal risk factors
Nutrition, stress, age
Influences on prenatal development- Environmental risk factors
Teratogens
Influence on prenatal development – Nutrition
Not enough macro nutrients such as proteins and micro nutrients such as iron lead to problems with attention, memory, and intelligence
Influences on prenatal development – stress
Links between maternal anxiety levels
Babies are born sooner
Lower birth weight
Attention problems behavioral issues
Influences on prenatal development – Maternal Age
Maternal age of both extremes (youth and advanced age) can be considered “risk factor”
Youth: premature birth, low birth weight, low academic performance, behavioral issues
Why? Social stigma and challenges faced by teen mothers and certain characteristics are more prevalent teen mom populations
Advanced age (40-45): miscarriage, low birth weight, Down syndrome
Teratogens
Any environmental agent that causes birth defects (example: alcohol, Zika virus)
Severity and type of damage depends on: does, genetic suspect ability, timing of exposure, presence of other negative factors.
Ultrasound
Procedure that uses soundwaves to generate a picture of the fetus
Can be used as early as 4 to 5 weeks post conception
It is used to: determine due date, position of the fetus, major abnormalities, detect multiples, determine sex (after 20 weeks)
Amniocentesis
A needle is inserted through the mothers abdomen to obtain a sample of amniotic fluid
Utilized in identifying genetic disorders
Chorionic Villus Sampling (CVS)
Utilized in identifying genetic disorders
A sample of tissue is obtained from a part of the placenta
Three stages of the birthing process
Pushing, crowning, afterbirth
Stage one of birth process
Stage one (12 to 24 hours)
Typically most painful part of birth
Contractions start week and a regular but by the end contractions are intense and sometimes without interruption
End of stage one the cervix and enlarges (dilates) to 10 cm
Stage two of birth process
Baby moves through the birth canal (1 hour)
Women feel strong urge to push and begin using abdominal muscles
Crowning: the babies head becomes visible
Breech: the baby moves down the birth canal feet or bottom first
Stage three of birth process
Typically takes 10 to 15 minutes
Commonly referred to as “afterbirth”
Placenta and fetal membrane need to be expelled from- the uterus detaching of placenta from the uterus
Postpartum depression (PPD)
A mood disorder that affects women after childbirth (goes on longer and is more severe than “baby blues”)
“Baby blues”
A range of negative emotions that typically last 1 to 2 weeks past birth (example: feelings of resentment irritation and crying spell)
Four states of the newborn
Alert inactivity, waking inactivity, crying, sleeping
Eight hours of quiet sleeping Eight hours of active sleeping One hour of drowsing Two hours of crying 2 1/2 hours of alert awake 2 1/2 hours of active away
The newborn – crying
Newborn spend 2 to 3 hours each day crying
Three distinct types of crying: basic crying, mad crying, pain crying
The newborn – sleeping
Newborn spend 16 to 18 hours a day sleeping
Typically via naps
Cycle of wakefulness and sleep every 4 hrs
Sleep believe to be needed for brain development
Sudden infant death syndrome (SIDS)
Usually around 2 to 4 months
Cause is unknown
Risk factors: prematurity, Low birth weight, parents smoke, sleep on stomach, winter (put to sleep in warm clothing)
Campaign against SIDS
Safe sleeping:
Place infants on their back or side, hard mattress and remove excess bedding, do not overdressed, do not wrap tightly in blankets
The newborn – reflexes
Organized newborn behaviors that occur in response to particular stimuli
rooting, sucking, stepping, babinski, grasping, moro
Newborn – rooting
When are newborn automatically turns their face towards a stimuli when their cheek or lips touched
(Birth- four month, can last up to 12 months)
Believed to occur to aid breastfeeding, not a sign of necessary hunger
Newborn- sucking
Related to rooting
When the roof of the baby’s mouth is touched it will begin to suck
(Develops during 32-36 weeks of pregnancy)
Assists in Feeding and replaced by voluntary sucking around 4 months
Newborn- stepping
Baby appears to take steps or “dance “when held upright with feet touching a solid surface
(birth- two months, assist in voluntary walking, reappears around one years of age)
Newborn – Babinski
When sole of foot stroked, the toes fan out and curl as the foot twist
(Birth – 12 months, Signals low myelination of the corticospinal tract, sign of disorder
Newborn – grasping
Infant will spontaneously grasp on to an object pressed against their palm
(birth – five months, prepares for voluntary grasping, similar reflex is also present in the toes until 9–12 months)
Newborn – Moro
When startled by a loud noise or movement, the baby will throw his head back, extend arms and legs, and then pull arms and legs back in
(birth – six months, it helps shield from danger)
