Topic 4: Prenatal Development and Birth

embryonic period%$$$??#?

---> week 3-8 -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 -sex organs formed or forming -Heart begins to pulsate -Extremities develop and webbed fingers and toes separate

anoxia related factors?

a lack of oxygen that, if prolonged, can cause brain damage or death 1. Genes 2. Birthweight 3. Gestational age 4. Drugs in bloodstream

postpartum depression

a new mother's feelings of inadequacy and sadness in the days and weeks after giving birth 1. Feelings of sadness and inadequacy 2. Symptoms from baby blues to postpartum psychosis 3. May involve struggles with adequate baby care 4. Varied causes

characteristics of childbirth

depend on: 1.) parents' preparation 2.) position/size of fetus 3.) culture

fetus

developing organism from week 9 after conception until birth

Reflexes that aid survival To maintain constant body temperature

shivering Tucking legs close to body Pushing/thrashing

swimming reflex

when laid horizontally on their stomachs, infants stretch out their arms and legs.

newborn adaptation gastrointestinal

x

newborn adaptation hematopoietic

x

newborn adaptation hepatic

x

newborn adaptation thermogenic

x

newborn adaptation hyperbilirubinemia

xh

beginning of pregnancy

-begins at conception (gestational age) -embryo not made until 2 weeks later -pregnancy does not affect the woman until 2 weeks later

apgar scale

-assessment of a newborn's health, given twice (1 & 5 mins. after birth) -scale of 1 to 10 -Rarely do we get 10 because of the color

implantation

-begins 10 days after conception -developing organism attaches to placenta that lines the uterus

Chorionic villus sampling (CVS)

1. Determine karyotyping & chromosomal abnormalities 2. Done between 9 to 11 weeks 3. Results within 1 week 4. 0.5% to 2.0% chance of pregnancy loss & limb abnormality

due date

-only 5% of babies are born on the exact due date

Consequences of Low Birthweight

1. Are later to smile, to hold a bottle, to walk, and to communicate 2. Have smaller brain volume Cognitive difficulties, visual/hearing impairments Neurological issues Behavioral difficulties

Parent-Infant Bonding

1. Bonding involves strong, loving connection that forms as parents hold, examine, and feed the newborn. 2. Early skin-to-skin contact is not essential for human bonding. 3. kangaroo care

Threshold effect

1. Certain teratogens are relatively harmless until exposure reaches a certain level. 2. thresholds are controversial

stages of labor

1. Cervix dilates to 10cm to allow passage of baby's head 2. Transition: baby's head moves into birth canal 3. Second Stage: baby's head "crowns" (moves through the opening of the vagina), Baby emerges completely 4. Third Stage: Expulsion of the placenta

Induced labor

1. Drug used to start, speed, or strength labor 2. Increase rate; now used in about 20% of U.S. births

Prenatal Diagnosis

1. Early care protects fetal growth, makes birth easier, and renders parents better able to cope. 2. When complications arise, early recognition increases the chance of a healthy birth. 3. About 20% of early pregnancy tests raise anxiety instead of reducing it. --False positives

birth

1. Fetal brain signals the release of hormones, especially oxytocin 2. Prepares the fetus for delivery 3. Starts labor 4. Typically lasts 12 hours for first births 5. Shorter labor for subsequent births 6. Birthing positions vary

Epidural

1. Injection in particular part of spine to alleviate pain 2. Often used in hospital births 3. Increase rate of cesarean sections and decrease the readiness of newborn infants to nurse Criticism that epidural slows down labor

Parental Alliance

1. Involves commitment by both parents to cooperate in raising the child 2. Is especially beneficial when infant is physically vulnerable cooperation between a mother and father based on mutual commitment to the child. In a parental alliance, the parents support each other in their shared parental roles.

Low Birthweight and the Mother

1. Maternal health and illness 2. Maternal drug use before and during pregnancy 3. malnutrition

genetic vulnerability

1. Some zygotes carry genes that make them vulnerable. 2. Male fetuses are more vulnerable to teratogens than female ones. 3. Mother's genes affect the prenatal environment she provides. 4. Neural-tube defects are more common in certain ethnic groups (e.g., Irish, English, and Egyptian).

germinal period

1. The original zygote as it divides into (a) two cells, (b) four cells, and (c) eight cells 2. Occasionally at this early stage, the cells separate completely, forming the beginning of monozygotic twins, quadruplets, or octuplets.

doula

1. Woman who helps with labor, delivery, breast-feeding, and newborn care 2. May be related to lower rate of cesarean sections

Alternatives to Hospital

1. home births 2. birthing centers 3. doula

doppler flow study

1. type of ultrasound that uses sound waves to measure the flow of blood through a blood vessel 2. assess blood flow in the umbilical vein and arteries, fetal brain, fetal heart, and other organs.

three periods of prenatal development

1.) Germinal Period (1st two weeks after conception): -Rapid cell division and beginning of cell differentiation 2.) Embryonic Period (3rd through 8th week): -Basic forms of all body structures develop 3.) Fetal Period (9th week until birth): -Fetus grows in size and matures in functioning

brain development (middle 3 months)

1.) 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

full term preterm postterm

1.) full term: 3 weeks before, 2 weeks after 2.) preterm: > 3 weeks before 3.) post-term: > 2 weeks after

vulnerability during prenatal development (% of survival)

1.) germinal: 60% fail to implant/grow 2.) embryonic: 20% are aborted spontaneously 3.) fetal: 5% are aborted spontaneously before viability at 22 weeks or stillborn 4.) birth: 31% grow and survive

childbirth in developed nations

1.) sterile procedures 2.) electronic monitoring 3.) drugs to dull pain/speed contractions

Amniocentesis

1.Obtain amniotic fluid 2. Identify chromosomal or biochemical abnormalities

length of pregnancy

266 days/38 weeks/9 months

trimesters

3 month periods instead of germinal, embryonic, and fetal

extremely low birth weight

<2 pounds 3 oz

very low birth weight

<3 pounds 5 oz

low birth weight

<5.5 pounds

Behavioral teratogens

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

Prenatal teratogens

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

Advice from Doctors: Problems

Doctors aren't always careful 1. Giving drugs that aren't declared safe 2. Failure to take time to understand woman's life patterns, Don't advise women about harmful life patterns like drinking

neonatal heat loss

Evaporation Conduction Convection Radiation

fathers Indirect influence of risk for adverse birth outcomes

Father's attitude Father's behavior Relationship between mother and father Hispanic paradox

zygote

Formed by the union of two gametes (1 sperm and 1 ovum) Contains all a person's genes

hispanic paradox

Many immigrants have difficulty getting well-paid jobs, and thus are of low socioeconomic status. Low SES correlates with low birthweight. Thus, their new- borns should be more often underweight. But, paradoxically, newborns born in the United States to immigrants are generally healthier in every way, including birthweight, than newborns of U.S.-born women of the same gene pool Perhaps fathers and grandparents keep pregnant immigrant women drug-free and healthy. The same is now apparent for immigrants from the Caribbean, from Africa, from Eastern Europe, and from Asia compared to U.S.-born women of those ethnicities.

Advice from Scientists: Problems

Provision of contradictory interpretation of research that led to opposite message Scientists interpret research in contradictory ways 1. Eating fish 2. Bisphenol A

Risk Analysis Factors

Risk analysis discerns which chances are worth taking and how risks are minimized. 1. Critical time 2. Dose and/or frequency of exposure (threshold effect) 3. Innate vulnerability

couvade

Symptoms of pregnancy and birth experienced by fathers

Babinski reflex

When feet are stroked, their toes fan upward.

Stepping reflex

When held upright with feet touching a flat surface, infants move their legs as if to walk.

Moro reflex

When someone startles them, infants fling their arms outward and then bring them together on their chests, as if to hold on to something, while crying with wide-open eyes.

Palmar grasping reflex.

When something touches infants' palms, they grip it tightly.

small for gestational age (SGA)

a term for a baby whose birth weight is significantly lower than expected, given the time since conception. For example, a 55 pounds newborn is considered SGA if born on time but not SGA if born 2 months early

Reflexes that aid survival To maintain oxygenation

breathing Hiccuping sneezing

fetal period in 3rd month middle 3 months final 3 months

in the 3rd month -Rapid growth with considerable variation -Average: 3 months; 3 ounces; 3 inches -9th week: SRY gene triggers development of sex organs -3rd month: can differentiate sex-> ultrasound ---> middle 3 months -Digestive and excretory system develop -Fingernails, toenails, and buds for teeth form, and hair grows (including eyelashes) -viable @ 22 weeks-> can survive outside of mother's body -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 ---> final 3 months -Involves expansion and contraction of lungs -Includes final maturation of heart valves, arteries, and veins -growth/folding in cortex

Managing feeding

sucking rooting swallowing spitting up