WHAT WILL YOU KNOW?

When do the most important parts of the fetus form?

Does medical assistance safeguard or impede the birth process?

What usually occurs in the first few minutes of a newborn’s life?

Why do substances and circumstances sometimes harm the fetus and sometimes have no impact.

What are the immediate and long-term causes and consequences of low birthweight?

Why do some mothers suffer from postpartum depression, and how does that affect the baby?

Prenatal Growth

Three main periods of prenatal development

Germinal period

Embryonic period

Fetal period

Prenatal Growth

Can you define these terms related to

timing and technology?

Beginning of pregnancy

Length of pregnancy

Trimesters

Due date

Vulnerability During Prenatal Development

The Germinal Period (First 14 Days)

• About half of all conceptions fail to grow or implant properly and thus do not survive the germinal period. Most of these organisms are grossly abnormal.

The Embryonic Period (From Third Through Eighth Week)

• About 20 percent of all embryos are aborted spontaneously,** most often because of chromosomal abnormalities.

The Fetal Period (From Ninth Week Until Birth)

• About 5 percent of all fetuses are aborted spontaneously before viability at 22 weeks or are stillborn (defined as born dead after 22 weeks).

Birth

• About 31 percent of all zygotes grow and survive to become living newborn babies.

Germinal Period: First 14 Days

Zygote begins

duplication and division

within hours of

conception.

• Development of the

placenta

• Implantation (about 10

days after conception)

• Organism grows

rapidly

The Most Dangerous Journey

In the first 10 days after conception,

the organism does not increase in

size because it is not yet nourished

by the mother.

The Embryonic Period: From the Third

Through Eighth Week

Embryo

Primitive streak becomes the neural tube and

later forms the brain and spine of the CNS.

Head takes shape.

Eyes, ears, nose, and mouth form.

Heart begins to pulsate.

Extremities develop and webbed fingers and

toes separate.

The Embryonic Period

(a) 4 weeks past conception (b) 7 weeks

Fetus: From Ninth

Week Until Birth

The third month

–Rapid growth with

considerable variation

–Average: 3 months; 3

ounces; 3 inches

–9th week: SRY gene

triggers develop of sex

organs

–3rd month: Neurological

sex differences begin

Fetus: The Middle

Three Months

Middle three months

Digestive and excretory

system develop

Fingernails, toenails, and

buds for teeth form, and hair

grows (including eyelashes)

Fetus: The Middle Three Months

Brain

Experiences rapid growth

Follows proximodistal sequence from brainstem to

midbrain, to cortex

Develops many new neurons (neurogenesis) and

synapses (synaptogenesis)

Begins to regulate basic bodily functions as entire

CNS becomes responsive

Fetus: The Middle Three Months

Age of viability

•Age at which a preterm newborn may survive

outside the mother's uterus if medical care is

available

•About 22 weeks after conception

•Brain is able to regulate basic body functions

(e.g., breathing)

Fetus: The Final

Three Months

Last three months

Involves expansion and

contraction of lungs

Includes final maturation

of heart valves, arteries,

and veins

Provides time for

extensive growth and

folding in cortex

One of the Tiniest

Rumaisa Rahman was born after 26

weeks and 6 days weighing only 8.6

ounces (244 grams). She has a good

chance of living a full, normal life.

Prenatal Growth of the Brain

Birth

Fetal brain signals the release of hormones to trigger the female's uterine muscles.

Labor begins

• Average duration for firstborn babies: 12 hours

• Quicker labor for later-born babies

Birthing positions vary

• Sitting, squatting, lying down, water births

• Cultural and personal preference

A Normal, Uncomplicated Birth

The Newborn’s First Minutes

Newborns

Usually cry spontaneously

Color changes from bluish to pinkish

Eyes open, fingers grab, toes stretch

Newborn mortality = 1 in 250 in U.S.

Apgar scale

Quick assessment of newborn's heart rate, breathing, muscle tone, color, and reflexes

Completed twice (1 minute and 5 minutes after birth)

Score of 0, 1, or 2 in each category

Desired score: 7 or above

Criteria and Scoring of the Apgar Scale

Score Color Heartbeat Reflex

Irritability

Muscle

Tone

Respiratory

Effort

0 Blue, pale Absent No

response

Flaccid,

limp

Absent

1 Body pink,

extremities

blue

Slow

(below

100)

Grimace Weak,

inactive

Irregular, slow

2 Entirely

pink

Rapid

(over 100)

Coughing,

sneezing,

crying

Strong,

active

Good; baby is

crying

Medical Assistance

Characteristics of childbirth depend on several variables– Parents’ preparation

– Position and size of fetus

– Customs of culture

In most developed nations childbirth includes– Sterile procedures

– Electronic monitoring

– Drugs to dull pain or speed contractions

Medical Assistance

Surgery: Cesareans

• Are controversial

• Involve surgical birth

• Vary by rates and reasons for use

• Present advantages for hospitals; more

complications after birth

Too Many Cesareans or Too Few?

Rates of cesarean deliveries vary widely from nation to nation.

Latin America has the highest rates in the world (note that 40 percent of all births in Chile are by cesarean), and sub-Saharan Africa has the lowest (the rate in Chad is less than half of 1 percent).

The underlying issue is whether some women who should have cesareans do not get them, while other women have unnecessary cesareans.

Birth

Alternatives to hospital technology

Place of birth: Hospital labor room; birthing centers; home

Supports: Doulas

Home Births

Planned home births are more common in many

developed countries.

Almost all babies are born at home in poorer nations.

Some research indicate home births entail risks for the

baby.

Every study finds benefits for the mother.

Key to good choice is being “medically informed”.

What Is a Doula?

Person trained to support laboring woman

Time contractions

Provide encouragement

Do whatever else is helpful

Are particularly helpful for immigrant, low-income, or unpartnered women

Harm to the Fetus

Harmful substances

Prenatal teratogens

• Any agent or condition, including viruses, drugs, and resulting in birth defects or complications

Behavioral teratogens

• Agents and conditions that can harm the prenatal brain, impairing the future child's intellectual and emotional

Risk Analysis Factors

Risk analysis discerns which chances are

worth taking and how risks are minimized.

Critical time

Dose and/or frequency of exposure (Threshold

effect)

Innate vulnerability

Risk Analysis: How Much Is Too Much?

Threshold effect

Certain teratogens are relatively harmless until exposure reaches a certain level.

Thresholds are controversial.

Example: Alcohol consumption

Embryo exposed to heavy drinking can develop fetal alcohol syndrome (FAS).

FAS is more apparent when women are poorly nourished and cigarette smokers.

Risk Analysis: Innate Vulnerability

Genetic vulnerability

•Some zygotes carry genes that make them

vulnerable.

•Male fetuses are more vulnerable to teratogens

than female ones.

Mother’s genes affect the prenatal environment

she provides.

•Neural-tube defects are more common in certain

ethnic groups (e.g., Irish, English, and Egyptian).

Conflicting Advice

Advice from Doctors

Problems

• Provision of potentially

dangerous prescriptions for

pregnant women

• Failure to take time to

understand woman’s life

patterns

Advice from Scientists

Problems

• Provision of contradictory

interpretation of research that

led to opposite message

Internet site usage

• Many Internet sites provided

inadequate or incorrect

information about drug safety

What about the Father?

Indirect influence of risk for adverse birth

outcomes (Misra et al., 2010)

Father’s attitude

Father’s behavior

Relationship between mother and father

Immigrant paradox

What Do We Know?

Prenatal teratogens can cause

Structural problems during embryonic period and

several diseases throughout pregnancy

Behavioral problems and reproductive impairment

later in life

Social response to evidence is

controversial.

Prenatal Diagnosis

Early prenatal care may

Protect fetal growth

Make birth easier

Render parents better able to cope

Provide early recognition of potential problems

Raise anxiety

Present false positives

Trouble Ahead

Low Birthweight

Low birthweight (LBW)

Very low birthweight

(VLBW)

Extremely low birthweight

(ELBW)

PretermSmall for

gestational age (SGA)

Low Birthweight and the Mother

Maternal behavior

•Maternal health and illness

•Maternal drug use before and during

pregnancy

Consequences of Low Birthweight

High risk infants and children

Are later to smile, to hold a bottle, to walk, and to

communicate

Middle childhood, formerly SGA children

Have smaller brain volume

Remember that risk analysis gives odds, not

certainties!

The New Family: The Newborn

Brazelton Neonatal Behavioral

Assessment Scale (NBAS)

Test often administered to newborns that

measures responsiveness and records 46

behaviors, including 20 reflexes

Parents who watch their infant perform on the

NBAS are amazed at the newborn’s responses—

and this fosters early parent–child connection.

The New Family: The Newborn

Newborns seek to protect themselves

with three sets of reflexes

Maintaining oxygen: Breathing, hiccupping,

sneezing

•Maintaining constant body temperature: Crying,

shivering, tucking legs to body, pushing

•Managing feeding: Sucking, rooting, swallowing

The New Family: The Newborn

Other reflexes are not necessary for

survival but signify the state of brain and

body functions.

Babinski reflex

Stepping reflex

Palmar grasping reflex

Moro reflex

New Mothers

About half of all women experience physical problems after birth.

Between 8 and 15% of women experience postpartum depression.

• Feelings of sadness and inadequacy

• Symptoms from baby blues to postpartum psychosis

• May involve struggles with adequate baby care

• Varied causes

New FathersNot only fathers, but the entire social network and culture are crucial influences.

Father's role: Being there• Helping mother stay healthy

• Helping mother manage stress (affects fetus)

• Providing legal acceptance the birth

Couvade

Symptoms of pregnancy and birth experienced by fathers.

Parental Alliance

Involves commitment by

both parents to cooperate in

raising the child

Is especially beneficial when

infant is physically

vulnerable

Family Bonding

Parent-infant bond

• Bonding involves strong, loving connection that

forms as parents hold, examine, and feed the

newborn.

• Early skin-to-skin contact is not essential for

human bonding.