Prenatal Development & The Newborn
Prenatal Development:
Begins with conception and ends at birth. A full term pregnancy is typically 38 weeks
Three stages of Prenatal Development:
*Germinal Stage: Conception to 2 weeks
*Embryonic Stage: 2 - 8 weeks
*Fetal Stage: 9 weeks to birth
Germinal Period "Finding a place to live":
The stage of development that occurs from conception until 2 weeks
*The fertilized egg, known as a zygote, moves toward the uterus, a journey that
can take up to a week to complete.
*Cell division begins approximately 24 to 36
hours after conception
*The zygote has the genetic instructions for new individual
Placenta:
Specialized organ that provies nourishment and oxygen from mother to the
developing embryo through the umbilical cord.
*Also filters away waste products from the developing baby
*The zygotes inner cells become the embryo (the developing multicellular
organism attached to the uterus) and the outer cells become the placenta
Embryonic Period "Organizing Space":
The development period from implantation to 8 weeks of pregnancy, which the
major organ and structure of the organism develop.
*Critical stage for "normal" cognitive and physical development
*Heart begins to beat, organs function
*The new individual is now considered an embryo
Fetal Period "Finishing Touches":
The development time period from nine weeks after conception until after the
birth of the child
*Fetus: Name for the developing organism from eight weeks after fertilization
to the birth of the baby (Sexual Differentiation)
*Fetus will gain weight and strength, brain is completely formed by the time of
birth
Critical Periods:
Times during which certain environmental influences can have an impact on the
development of the infant (Embryonic Period)
*Birth Defects: Can result from a malfunctioning gene or an environmental
stimulus (not hereditary)
Teratogen:
Agents, such as chemicals and viruses, that can reach the embryo or fetus
during prenatal development and cause harm
*The effects of exposure to any teratogen will depend on how much exposure
there is, when it happens, and how susceptible one is to that teratogen
Teratogen Agent: Stress
*Any form of prenatal stress felt by the mother can have negative effects on
various aspects of fetal development
*A stressed mother is more likely to engage in behaviours that could negatively
affect the fetus
Teratogen Agent: Alcohol
*Alcohol is not safe to drink in any amount during pregnancy
*Alcohol use during pregnancy has been found to be the leading preventable
cause of mental disabilities in children in the United States.
*Fetal Alcohol Syndrome (FAS): includes physical, cognitive, and psychological
abnormalities that result from consuming alcohol during pregnancy.
*Low intelligence, a small head with flat face, misshapen eyes, a flat nose,
and a thin upper lip
*Intellectual impairment ranges from minor learning disabilities to severe
intellectual disability
Teratogen Agent: Smoking/Nicotine
*When the mother smokes, the developing baby experiences a reduction in blood
oxygen levels & nutrients
*Smoking while pregnant can result in effects on fetal growth such as premature
birth, low birth weight infants, stillbirth, and sudden infant death syndrome (SIDS)
Teratogen Agent: Smoking/Marijuana
*It is recommended that pregnant women do not use marijuana (CDC)
*Smoking marijuana while pregnant can result in low birth weight, developmental
problems, difficulty with attention
Teratogenic Agent: Prescription and/or Illegal Drugs
*Use of any type of drug-whether illegal, prescription, or over-the-counter can
be dangerous during pregnancy
*Illegal Drugs: Babies can be born addicted, born prematurely, have low birth
weight, and experience other physical defects. Many end up with attention and
behavioural problems as well
Reflexes:
Infants have a set of innate (existing from birth) unlearned behaviour patterns
to help the infant to survive.
*Grasping, Rooting, Sucking, Moro Reflex, Stepping, Babinski Reflex
*Reflexes allow infants to receive food or to cling to a caregiver in early days
of their lives (disappear in first 6 months of life)
*The sense of touch is the most well developed in infancy and the sense of smell
is highly developed (taste and hearing nearly functional)
*The least functional sense at birth is vision. It takes six months to fully
develop (Attracted to light-and-dark contrasts)
Neonates (Infant less than 4 weeks)
*Neonates turn their heads in the direction of human voices
*Neonates are born with a preference to look toward faces, 8 to 12 inches away
*Neonates know the difference in smell, babies preferred breast pads to their
moms or others
At birth, most brain cells are present. After birth, the neural networks
multiply resulting in increased physical and mental abilities (increased complexity)
*Blooming: Period of rapid neural growth
Maturation:
Biological growth processes that enable orderly changes in behaviour, relatively
uninfluenced by experience
*Genetic growth tendencies are inborn, determined by genetic makeup
*Maturation sets the basic course of development; experience adjusts it
Development Norms:
The normal timeline of mental and physical growth and changes that occur as an entity ages
*If a baby has not reached a developmental norm within a normal time frame then
there is a possibility that they may have a development delay
Six Motor Milestones:
Infant's muscles and nervous system mature, skills emerge
*Sit, Crawl, walk, run - the sequence of these motor developments milestones is
the same the world around, though babies reach them at varying ages
Infantile Amnesia:
The difficulty or inability that adults have in remembering detailed or episodic
memories (memories were time, place and events can be identified) from early
childhood, generally prior to age 3 or 4
*Infants can learn skills (procedural memories)