Fundamentals of
Lifespan Development
JANUARY 20 – PRENATAL DEVELOPMENT AND BIRTH
Video
Video – 9 Months in the Womb
Footage of Baby in the Womb
3D Video of Conception to Birth
Life’s Greatest Miracle – PBS NOVA
Germinal Stage – Conception and
Implantation
Implantation:
◦ Amniotic Fluid – Fluid for temperature &
protection
◦ Placenta – Food & oxygen & waste
◦ Umbilical Cord – Delivers blood & removes
waste
◦ Zygote – New cell produced by combining two
gametes
◦ Gamete – Ovum and sperm with 23
chromosomes
Milestones of Prenatal Development
Trimester
Period
Weeks
Length and Weight
Major Events
First
Zygote – Germinal Stage
1
Conception. One cell
multiplies & forms blastocyst.
Zygote - Implantation
2
Blastocyst begins
implantation
Embryo - Organogenesis
3-8
6 mm
Primitive brain & spinal cord.
Organs begin to grow
Embryo
5-8
2.5 cm
4g
External body parts grow.
Embryo can move. Gonad
and genital development.
Fetus
9-12
7.6 cm
28 g
Rapid increase in size.
Internal organs become
organized.
Second
Fetus
13-24
30 cm
820 g
Fetus enlarges. Fetal
movements felt by mother.
Sensitive to light & sound.
Third
Fetus
25-38
51 cm
3200 g
Size increases. Organs
mature. Fat is added.
Antibodies are transmitted.
Fetal Stage Milestones
Weeks
Major Events
9 – 12
Fingerprints, grasping reflex, facial expressions, swallowing, rhythmic ‘breathing’ of amniotic fluid, urination, genitals appear, activity &
rest.
13 – 16
Hair follicles, respond to mothers voice and other loud noises
17 – 20
Fetal movements felt by mother, heartbeat detectable with stethoscope, lanugo covers body, eyes respond to light, eyebrows, fingernails
21 – 24
Vernix protects skin, lungs produce surfactant, vitality possible but problematic
25 – 28
Recognition of mother’s voice, regular periods of rest and activity, good chance a newborn would survive
29 – 32
Very rapid growth, antibodies acquires, fat deposits under skin
33 – 36
Movement of head for birth, lungs mature
37 +
Full-Term
Pregnancy Summary
Genetic Disorders
Teratogens
Agents that causes damage to an embryo or fetus during the prenatal period.
 Drugs – Legal and Illegal
 Alcohol
 Tobacco
 Radiation
 Pollution
 Infectious disease
 Nutrition (maternal factor)
 Stress (maternal factor)
 Maternal Age
 Rh factor incompatibility
3 types
Mutagenic – Cause alterations to genomic
DNA
Environmental – Environmental agents that
disrupt normal cell development
Epimutagenic – Cause alterations with
epigenetic structures without changing the
DNA
Teratogens
Childbirth
Stages of childbirth:
1. Dilation and effacement of the cervix
◦ First birth = 12 – 14 hours
◦ Second + = 4-6 hours
2. Delivery of the baby
◦ First birth = 50 min
◦ Second + = 20 min
3. Delivery of the placenta
◦ 5-10 min
The Apgar Scale
Childbirth Key Terms
Breech position – When a baby is turned so that the buttocks or feet would be delivered first
Anoxia – Inadequate oxygen supply during labour and delivery
Isolette – Plexiglas-enclosure to protect preterm babies
Cesarean – A surgical birth where a doctor makes an incision in the mother’s abdomen and lifts
the baby out of the uterus
Discussion
How were you born?
1 – In a hospital
2 – In a birthing center
3 – At home
4 – Other
Why did your parents chose that location?
What did (would) you do if you (or a partner) were going to have a child?