Prenatal Development Flashcards
Steps from Conception to Implantation
- Zygote, 2. Blastocyst, 3. Implantation
Prenatal Development: Zygote
Implantation; Placenta and Umbilical Cord
Implantation (Zygote)
- Trophoblast forms the amnion which encases the embryonic disk in amniotic fluid
- Development of a nourishing yolk sac
Placenta and Umbilical Cord (Zygote)
- Trophoblast develops the chorion which surrounds the amnion (Development of villi)
- Development of placenta
Embryo Wk 2-4
Formation of the 3 layers of cells; Neural tube formation
Embryo Wk 4-8
- Structural foundations: eyes, ears, nose, jaw, neck, and buds for arms, legs, finger sand toes
- Neuron production
- Sensory abilities and small movement
Fetus Month 3
- Organization of muscles and nerves permit more coordinated movement
- Structural details complete
- Sex can be determined at 12 weeks
Fetus Second Trimester
- Vernix and lanugo development
- Glial cell and synaptic connection formation permits greater, purposeful movement capacities
Fetus Third Trimester
- Age of viability
- Sleep/wake cycle is more predictable
- Activity level increases Habituation and learning capabilities
Threats to Fetal Development
Teratogens
Teratogens
- Drugs
- Disease
- Poison
- Alcohol
- Smoking
- Radiation
Impact of Teratogens on developing fetus depends on…
- Dose
- Frequency
- Heredity
- Age
- Other negative influences
Teratogens effects during period of dividing Zygote, Implantation
Usually not susceptible to teratogens (Prenatal Death)
Teratogens effects during embryonic period (in weeks)
3: CNS; 4-5: Eyes, Heart, Arm, Leg; 6: Teeth, Ear; 7: Palate; 8: Ear, External Genitals (Major Structural Abnormalities)
Teratogens effects during Fetal Period (in weeks) Full Term
9: Brain, External Genitals; 16: Brain (Physiological effects and Minor Structural Abnormalities)
Maternal Factors in Infant Development
- Infectious Diseases
- Nutrition
- Emotional Stress
- Rh Blood Factor
- (Maternal) Age
Prenatal Development and Later Health
Low/High Birth Weight
Low Birth Weight (Prenatal Development and Later Health)
Greater chance of Heart Disease, Stroke, Diabetes
High Birth Weight (Prenatal Development and Later Health)
Greater chance of breast cancer
Stage 1 of Birth
Dilation and Effacement; Transition
Dilation and Effacement (A: Stage 1 of Birth)
Contractions of the uterus cause dilation and effacement of the cervix
Transition (B: Stage 1 of Birth)
Transition is reached when the frequency and strength of the contractions are at their peak and the cervix opens completely
Stage 2 of Birth
Pushing; Birth of the Baby
Pushing (C: Stage 2 of Birth)
The mother pushes with each contraction, forcing the baby down the birth canal, and the head appears
Birth of the Baby (D: Stage 2 of Birth)
Near the end of stage 2, the shoulders emerge and are followed quickly by the rest of the baby’s body
Stage 3 of Birth
Delivery of the Placenta
Delivery of the Placenta (E: Stage 3 of Birth)
With a few final pushes, the placenta is delivered
Birthing Methods
- Drug-assisted Childbirth
- Natural Childbirth
- Home Delivery
- Water Birth
Drug-assisted Childbirth (Birthing Methods)
-Utilization of drugs and medical equipment to ease the pain of childbirth
Natural Childbirth (Birthing Methods)
-Birthing classes
Relaxation and breathing techniques
Labor coach
Home Delivery (Birthing Methods)
- Using a mid-wife
- Generally recommended for healthy births
Water Birth (Birthing Methods)
- Mother is placed in shallow pool of water
- Believed to be relaxing and provide more positive experience
The APGAR Scale
-Appearance
-Pulse
-Grimace
-Activity
-Respiration
(Usually done twice before baby is allowed to leave the hospital)
Are Preterm or Small-for-Date babies at greater risk?
Small-for-Date
Preterm Babies
- Born weeks before their due date
- May be appropriate weight for length of pregnancy
Small-for-Date Babies
- May be born at due date or preterm
- Below expected weight for length of pregnancy
Interventions for Preterm Infants
- Isolette (Respirator, Feeding tube, Intravenous medication)
- Special Infant Stimulation (Kangaroo care)
- Parent Training in Caregiving
New Born Reflexes
- Eye Blink
- Rooting
- Sucking
- Moro
- Palmar Grasp
- Stepping
- Babinski
Infant States
- Regular, NREM sleep
- Irregular, REM sleep
- Drowsiness
- Quiet Alertness
- Waking activity and crying
Regular, NREM sleep (Infant States)
At full rest with little to no body activity, eyes are closed, lids not moving
Duration: 8-9 hours
Irregular, REM sleep (Infant States)
Gentle limb movements and irregular eye movement under lids. Occasional grimacing and irregular breathing
Duration: 8-9 hours
Drowsiness (Infant States)
Either falling asleep or waking up. Less active than irregular sleep but more active than regular sleep
Duration: Varies
Quiet Alertness (Infant States)
Relatively inactive body but eyes are open and baby is attentive
Duration: 2-3 hours
Waking activity and crying (Infant States)
Frequent bursts of uncoordinated activity. Irregular breathing. Crying may occur. Face may be relaxed or wrinkled.
Duration: 1-4 hours
Crying
- Crying is one of the first ways in which babies communicate with the outside world
- Crying behavior peaks at 6 weeks then declines
- Infants who are pre-term or have had birthing complications may have a shrill, piercing cry
Crying happens for many different reasons:
- Physical needs (hunger)
- Temperature change
- Sudden noises
- Painful stimulus
- Sound of another baby crying
Newborn Sense of Touch
- Sensitive to touch on mouth, palms, soles, genitals
- Highly sensitive to pain (Relieve pain with anesthetics, sugar solution, gentle holding; Physical touch releases endorphins)
Newborn Senses of Taste
- Prefer sweet tastes at birth
- Quickly learn to like new tastes
Newborn Senses of Smell
- Have odor preferences from birth
- Can locate odors and identify mother by smell from birth
Newborn Senses of Hearing
- Can hear a wide variety of sounds at birth
- Prefer complex sounds to pure tones
- Learn sound patterns within days
- Sensitive to voices and biologically prepared to learn language
Newborn Sense of Vision
- Least developed sense at birth
- Limited acuity
- Scan environment, track moving objects
- Color vision improves in first two months
Zygote (1)
Fertilized egg= zygote; As the zygote moves down the Fallopian tube, it duplicates, at first slowly and then more rapidly
Blastocyst (2)
By the fourth day, it forms a hollow fluid-filled ball, called a blastocyst. The inner cells, called the embryonic disk, will become the new organism. The outer cell, or trophoblast, will provide protective covering
Implantation (3)
At the end of the first week, the blastocyst begins to implant in the uterine lining
