Prenatal Development and Birth Flashcards

Typical Prenatal Development

begins with fertilization and ends with birth
takes between 266 to 280 days (38 to 40 weeks)
divided into three periods:
1. germinal
2. embryonic
3. fetal

The Germinal Period

takes place in the first two weeks after conception
includes the creation of the fertilized egg (called a zygote), cell division, and the attachment of the zygote to the uterine wall

Blastocyst

the inner layer of cells that develops during the germinal period
these cells later develop into the embryo

Trophoblast

the outer layer of cells that develops in the germinal period
these cells provide nutrition and support the embryo

Implantation

the attachment of the zygote to the uterine wall
takes place 11 to 15 days after conception

The Embryonic Period

the period of prenatal development that occurs from two to eight weeks after conception
begins as the blastocyst attached to the uterine wall
the rate of cell differentiation intensifies
support system for cells form
organs appear
three layers of cells:
- endoderm
- mesoderm
- ectoderm

Embryo

mass of cells

Endoderm

inner layer of cells
will develop into the digestive and respiratory systems

Mesodem

middle layer of cells
will develop into the circulatory system, bones, muscles, excretory and reproductive system

Ectoderm

outermost layer of cells
will become the nervous system and brain, sensory receptors and skin parts

Amnion

the life support system
bag-like
contains a clear fluid (amniotic fluid) in which the developing embryo floats

Amniotic Fluid

provides an environment that is temperature and humidity controlled
shook proof

Umbilical Cord

a life support system
contains 2 arteries and one vein
connects the baby to the placenta

Placenta

life support system
consists of disk-shaped group of tissues in which small vessels from the mother and offspring interwine

Organogenesis

organ formation
takes place during the first two months of prenatal development
organs are especially vulnerable during this time
third week after conception = neural tube that eventually becomes spinal cord forms
about 21 days: eyes begin to appear
24 days: the cells of the heart begin to differentiate

Fetal Period

lasts about seven months
prenatal period between 2 months after conception to birth

The Brain & Prenatal Development

neurons handle information processing at the cellular level in the brain
babies have approx 100 billion neurons by the time they are born
the third trimester of prenatal development and the first 2 years of postnatal life are characterized by connectivity and functioning of neurons

Neurons

nerve cells, which handle information processing at the cellular level in the brain

Nervous System & Prenatal Development

the nervous system begins forming as a long, hollow tube located in the embryos back
forms about 18 to 24 days after conception

Anencephaly

the highest regions of the brain fail to develop
or when head end of the neural tube fails to close
baby dies in the womb, during childbirth or shortly after birth

Spina Bifida

results in varying degrees of paralysis of the lower limbs
usually needs assistive devices: such as crutches, braces, or wheelchairs
risk factors: maternal diabetes and obesity
preventive measures: mother take adequate amounts of vitamin B folic acid

Neurogenesis

the generation of new neurons

Neuronal Migration

involves cells moving from their point of origin to their appropriate location
occurs at approx. 6 to 24 weeks
Once a cell has migrated to its target destination, it must mature and develop a more complex structure

Teratogen

any agent that can potentially cause a birth defect or negatively affect cognitive and behavioral outcomes
Ex:
- food
- drugs
- chemical toxins

Teratogen Influence

Dose
- the greater the dose of an agent the greater the effect
Gene Susceptibility
- the type or severity of abnormalities caused by a teratogen is linked to both the genotype of the pregnant mother and fetus/embryo
Time of Exposure
- exposure to teratogens does more damage when it occurs at some points int development that at others

Critical Period

a fixed time period very early in development during which certain experiences or events can have a long-lasting effecting on development

Teratology

field of study that investigates the causes of birth defects

Fetal Alcohol Spectrum Disorder

a cluster of abnormalities that appear in the offspring of mothers who drink alcohol heavily during pregnancy
Abnormalities
- facial deformities
- defective limbs, face, and heart
- learning problems

Normal Gestational Weight Gain

11 to 20 pounds

Prenatal Care

involves a defined schedule of visits for medical care
includes:
- screening for manageable conditions & treatable diseases (that can affect the baby or mother)
- comprehensive educational, social, and nutritional services
- exercise regularly
  - helps prevent constipation
  - conditions the body
  - reduces excessive weight gain
  - positive mental state

Stages of Birth

(first stage)
- uterine contractions are 15 to 20 minutes apart and last up to a minute
- these contractions cause the woman's cervix to stretch and open
- at the end of the first birth stage, contractions dilate the cervix to an opening of about 10 cm (4 in)...so baby can move from the uterus to the birth canal
- lasts an average of 6 to 12 hours
(second stage)
- begins when the baby's head starts to move through the cervix and the birth canal
- typically lasts 45 mins to 1 hr
(third stage)
- afterbirth
  - the placenta, umbilical cord, and other membranes are detached and expelled
  - lasts only a few minutes

Childbirth Setting & Attendants

in the US 99% of births take place in hospitals
Midwife
- a person qualified to deliver babies and to care for women before, during, and after childbirth
Doula
- a caregiver who provides continuous physical, emotional, and educational support for the mother before, during, and after childbirth

Midwife

a person qualified to deliver babies and to care for women before, during, and after childbirth

Doula

a caregiver who provides continuous physical, emotional, and educational support for the mother before, during, and after childbirth

Methods of Childbirth

Medication
Natural and Prepared Childbirth
Cesarean Delivery

Medication (methods of childbirth)

Analgesia
- used to relieve pain
Anesthesia
- used in late first stage of labor
- blocks sensation in an area of the body
- or block consciousness
- epidural block
  - regional anesthesia that numbs the woman's body from the waist down
Oxytocin
- a synthetic hormone
- used to stimulate contractions
- pitocin (example)

Natural Childbirth

method that aims to reduce the mother's pain by decreasing her fear
done through education about childbirth
teaching breathing methods and relaxation techniques during delivery

Prepared Childbirth

special breathing technique to control pushing in the final stages of labor
detailed anatomy and physiology course

Cesarean Delivery

surgical procedure in which the baby is removed from the mother's uterus through an incision made in her abdomen

Breech Position

the baby's position in the uterus causes the buttocks to be the first part to emerge from the vagina

Apgar Scale

scale used assess the health of newborns at one and five minutes after birth
evaluates an infants heart rate, respiratory effort, muscle tone, body color, and reflex irritability
total score of 7 - 10 indicates that the newborn is in good condition

Brazelton Neonatal Behavioral Assessment Scale (NBAS)

a measure that is used in the first month of life to assess the newborn's neurological development, reflexes, and reactions to people and objects

Low Birth Weight Infants

weigh less than 5½

Preterm Infants

infants born before the completion of 37 weeks of gestation

Small for Date Infants

infants whose birth weights are below normal when the length of pregnancy is considered

Nurturing Low-Weight and Preterm Infants

kangaroo care
massage therapy

Kangaroo Care

involves skin to skin contact between baby and mother
2 to 3 hours per day
helps to stabilize the preterm infant's heartbeat, temperature, and breathing

Postpartum Period

the period after childbirth when the mother adjusts both physically and psychologically, to the process of childbirth

Physical (postpartum adjustments)

fatigue
hormonal changes

Emotional & Psychological (postpartum adjustments)

Postpartum Depression
- major depression episode
- typically occurs about 4 wks after delivery
- strong feelings of sadness, anxiety, or despair

Life-Span Development: Prenatal Development and Birth Flashcards