ch 3 -- prenatal development, birth, and the newborn

division of time

1) REM - 8-9 hrs 2) non REM - 8-9 hrs 3) drowsiness - varies 4) quiet alertness - 2-3 hrs 5) waking activity and crying - 1-4 hrs

three layers of cells

1) ectoderm - nervous system and skin 2) mesoderm - muscles, skeleton, circulatory system, other internal organs 3) endoderm - digestive system, lungs, urinary tract, and glands

what are the three periods of pregnancy?

1) germinal period (first 2 weeks) 2) embryonic period (week 3 - 8) 3) fetal period (week 9 - full term) pregnancy is around 38 weeks long; the 40 weeks just includes the first couple weeks since last period.

what are the critical aspects of prenatal care for women?

1) nutrition 2) regular check-ups 3) HIV testing 4) infection prevention 5) alcohol, tobacco, and other drug use avoidance

teratogen

any environmental agent that causes damage during prenatal period. depends on dose, heredity, age of organism, and other negative influences that might increase its harm. some health effects can show up yrs later, by epigenetically modifying gene expression. delayed psychological consequences can occur as well.

non REM sleep

body is almost motionless. heart rate, breathing, and brain wave activity are slow and uneven.

HIV testing and prenatal care

both testing and treatment if needed. in countries where HIV is more common especially, there is a risk that the mother can pass it on to the baby; however, this risk lowers substantially with treatment.

REM sleep

brain wave activity is remarkably similar to that of the waking state. eyes dart beneath lids, heart rate, blood pressure, and breathing are uneven; slight body movements occur.

external factors and SIDS

can't necessarily control early vulnerabilities or the critical period of development, but can control external stressors. 1) soft bedding -- can trap baby, leaving them to suffocate and not wake up. this is why parents have sometimes been advised not to co-sleep by doctors in Western countries. 2) having smoke in the household 3) parent intoxicated throughout the night; affects their ability to wake up in response to problems with their child 4) overheating 5) the stomach sleep position -- the Safe to Sleep campaign emphasizes the importance of infants sleeping on their backs, which does have the disadvantage of making it harder for them to fall asleep. SIDS is less common in non-industrialized nations because co-sleeping parents are closer to the baby and can more easily respond to disturbances.

smell

certain odor preferences are clear at birth. again, amniotic fluid differs in scent according to mother's diet, and baby's preferences reflect this. sense of smell helps babies and mothers ID each other. within early days, baby prefers odor of mother's breast to that of other women.

regular check-ups and prenatal care

check-ups necessary for general progress of pregnancy as well as risk factors (weight gain, blood pressure, etc.). blood pressure becomes esp. important in the latter half of pregnancy.

is co-sleeping risky? do industrialized or non-industrialized nations have higher rates of SIDS?

co-sleeping CAN be risky for SIDS if precautions are not taken, but it is not inherently more risky. in fact, non-industrialized nations do it more commonly than for example people in the US, and they have much lower rates of SIDS. often requires sleeping away from soft surfaces that could smother the baby, not wrapping them too tightly, and not having them sleep on stomach.

co-sleeping vs independent sleep

co-sleeping with infants is more common worldwide than in Western-oriented countries. makes sense when considering the popularity of individualism -- reliance on self-soothing, self-sufficiency, and independence -- vs collectivism. the social norm of "we must let the kid have its own space early" is powerful, but there is nothing wrong with co-sleeping across varying time periods.

abnormal crying

cries of brain damaged babies and those with prenatal and birth complications are often shrill, piercing, and shorter in duration than those of healthy infants. also common with colic, which occurs often in babies who react strongly to unpleasant stimuli, but declines between 3-6 months.

crying

crying is the first way infants communicate to let parents know they need food, comfort, or stimulation. varies in intensity, and sometimes strength of it + related context can help parents understand the cause. usually cry due to physical needs, but also temp change, sudden noise, painful stimulus, etc. also in reaction to another crying baby. typically increases during early weeks, peaks at 6 weeks, and then declines.

critical period and SIDS

during the critical period of development, there are rapid changes in the first 6 months of a baby's life, whether physiological or behavioral. these can leave babies at risk for SIDS. impaired brain functioning is a major contributor, as reflexes decline and are replaced by voluntary learned responses. neurological weaknesses may prevent SIDS babies from acquiring behaviors that replace defensive reflexes. because of this, they do not wake up when they start suffocating. maternal cigarette smoking doubles risk of disorder; it makes babies arouse less easily from sleep and have more respiratory infections.

sleep

enhances a baby's learning and memory. capacity to learn about external stimuli during sleep may be essential to adaptation to surroundings. made up of two states - REM and non REM sleep. newborns alternate between these, but spend more time in REM than other people until ~3 yrs. disturbed sleep cycles are often present in infants who are brain damaged or experienced birth trauma. show delayed motor, cognitive, and language developing in preschool kids. brain functioning problems related to this can result in SIDS.

germinal period

first period of pregnancy. lasts about two weeks, from fertilization and formation of zygote until implantation. by fourth date, 60-70 cells exist that form a blastocyst, which contains the embryonic disc, the inside cells of which become the new organism. the outer ring, the trophoblast, becomes the structures that will provide covering and nourishment.

physical vulnerabilities and SIDS

health issues that can affect infants like respiratory, breathing, and heart rate problems can all increase risk for SIDS. higher rates of prematurity and low birth weight, limp muscle tone, abnormal HR and respiration, disturbances in sleep-wake cycles. many SIDS babies have mild respiratory infection at time of death.

sensitive periods of pregnancy

if there is damage to the embryo due to a teratogen in the germinal period, spontaneous abortion will result. however, usually not as susceptible to teratogens. in the embryonic period, teratogens will cause major structural abnormalities in the embryo. largely affecting things like CNS, organs, eyes, ears, limbs. in the fetal period, teratogens will cause physiological defects and minor structural abnormalities, for instance in the external genitalia. damage usually minor, but organs like the brain, eyes, ears, and teeth can still be strongly affected.

drug use avoidance and prenatal care

important for mothers to avoid alcohol, tobacco, and other drug substances a lot of the time. also involves management for certain medications, like psychiatric meds, which require consultation with a care provider and are often not possible to just fully stop. hard to draw concrete conclusions on the effects of drugs/medications because they must ethically be correlational; cannot force pregnant people to take drugs just to see if it has bad effects on prenatal development.

video ex 2 -- barriers to prenatal care

in eastern Indonesia, women often give birth at home without assistance, and maternal and child death rates are high. health workers/midwives write friendly letters that invite women to come into nearby health clinics for help, and the tone serves as a basis for a kind relationship that the mother finds encouraging.

the second trimester

in fetal period. in motion 30% of time to strengthen joints and muscles. vernix emerges to protect skin from amniotic fluid, and lanugo appears to help vernix stick to body. at end of trimester, many organs well developed and most neurons in place. however, glial cells continue to increase rapidly over course of pregnancy and further. brain weight increases tenfold from 20th week until birth. neurons begin forming synapses at rapid pace. this brain growth means new sensory and behavioral capacities - can be stimulated and irritated by sounds, for ex. however, still cannot survive outside body because lungs immature and brain can't control body temp or breathing.

third month/rest of first trimester

in fetal period. organs, muscles, and nervous system start to become organized and connected. touch sensitivity expands. lungs begin rehearsing breathing. when brain signals, fetus sometimes responds, like by kicking. by end of 12th week, external genitals formed. heartbeat can be heard through stethoscope.

third trimester

in fetal period. soon reaches age of viability, though still would need O2 assistance to breathe. cerebral cortex (seat of human intelligence) enlarged. fetus spends more time awake. around 36 weeks, synchrony between fetal heart rate and motor activity peaks. show signs of developing temperament. greater responsiveness to external stimulation, including pain, sounds, etc. can soon distinguish between different sounds including parents' voices. fetuses gain weight to help with temp regulation, and receive antibodies from mother's blood to help immature immune system. growth slows closer to birth.

last half of first month in embryonic period

in last half of first month, the embryonic disk forms three layers of cells: ectoderm, mesoderm, and endoderm. nervous system develops fast, and ectoderm folds over to form neural tube (primitive spinal cord). heart begins to pump blood. muscles, backbone, ribs, and digestive tract appear. by end of this part, embryo is 1/4 in.

second month in embryonic period

in the second month, the eyes, ears, jaw, nose, and neck form, as well as buds for limbs. the internal organs become more distinct -- intestines grow, heart develops separate chambers, liver and spleen take of production of RBCs, posture becomes more upright. production of neurons happens at rate of 250,000 per minute. by end of this part, embryo can sense world, respond to touch, and move.

nutrition in infants

includes decisions such as: 1) breastmilk vs formula 2) if breastfeeding, how and when to wean/stop 3) first solid foods; when and which ideal is if parents have access to information and are able to make the best decisions that works for them and their families.

infection prevention and prenatal care

includes vaccines, condoms, basic hygiene, etc. also includes treatment -- rest and fluids, antibiotics, other medications.

SIDS

infants die often in the middle of the night due to Sudden Infant Death Syndrome. we still don't really know what causes it; however, there seems to be more of a risk if the infant has 3 or more complications or vulnerabilities (physical vulnerabilities, critical period, external factors). leading cause of mortality in the first year.

physical care for infants: needs vs norms

involves decisions that caregivers make and the influences behind them 1) sleep -- co-sleeping and sleep training 2) preventative healthcare 3) nutrition

sensitive period

limited time span in which part of body or behavior is biologically prepared to develop rapidly. during this time, it is especially sensitive to its surroundings; if the environment is harmful, then damage occurs, and recovery can be difficult and sometimes impossible.

video ex 1 -- barriers to prenatal care

many women in Ethiopia live in rural areas without medical access, and maternal morality rates are high. medical workers travel to these villages to set up health posts, letting pregnant women know about them so they can receive necessary medical care.

illegal drugs and teratogens

mood altering drugs lead to wide variety of problems, including prematurity, low birth weight, brain abnormalities, physical defect, breathing difficulties, and even death at birth. babies can also be born addicted. cocaine can interfere with production and functioning of neurons and the chemical balance of fetus's brain. linked to motor, attention memory, impulsivity, overactivity, and other issues later on.

conception

most conceptions occur in three day period, on day of ovulation or during the two days preceding it. male produces sperm in testes, which develop tails to swim long distances upstream in female reproductive tract. live up to 6 days and can lie in wait for ovum, which survives 24 hrs after release from ovary. about middle of menstrual cycle, ovum bursts from one of ovaries into Fallopian tube, CL secretes hormones that prepare lining of uterus to receive fertilized ovum. if not pregnant, CL shrinks and is discarded.

infectious diseases and teratogens

mothers with untreated HIV pass on the virus to their child 10-20% of the time. progresses rapidly in infants; most are ill by 6 months and dead by age 3. drug therapy, however, greatly reduces risk of transmission. also sensitivity to family of herpes viruses, and parasites like toxoplasmosis. mothers who become ill from rubella during embryonic period might have babies with deafness, eye deformities, heart, genital, urinary, intestinal, bone, an dental defects, and intellectual disability.

are newborn reflexes culturally dependent?

newborn reflexes are NOT culturally dependent; they are innate and universal.

do newborn reflexes form a basis for complex motor behaviors?

newborn reflexes do NOT form the basis for complex motor behaviors. the exception to this is the stepping reflex, which helps form the basis for walking later on.

do newborn reflexes have evolutionary explanations?

newborn reflexes do have evolutionary explanations. they have adaptive purposes. reflexes are also a sign of healthy, normative brain development. they are the most obvious organized patterns of behavior for newborns. most newborn reflexes disappear within 6 months due to gradual increase in voluntary control over behavior as cerebral cortex develops

taste

newborns can distinguish several different tastes. the food that best supports early growth is mother's breastmilk, which reflects preference for sweet tastes. amniotic fluid influences this preference, and varies with the diet of the mother. young infants will readily learn to prefer a taste that at first evoked a negative or neutral response.

hearing

newborns can hear wide variety of sounds, a sensitivity that improves greatly over first few months. at birth, prefer complex sounds to simple ones and can tell difference between a variety of sound patterns. young infants listen longer to human speech than structurally similar sounds. also make distinctions among many speech sounds, relating to ability to acquire language.

how much time do babies spend in REM sleep?

newborns spend ~50% of their sleep time in REM, which is huge in comparison to people of any other age. gradually, the amount of time in REM drops down through infancy and toddlerhood. the explanation for this is that REM helps with the large amount of learning and consolidating of information going on at this age.

is vision the most developed sense at birth?

no, vision is the least developed sense at birth.

nutrition and prenatal care

nutrition includes supplements, as well as advice and access. skilled advice specifically, from medical professionals. for ex., folic acid is very important early in pregnancy because it protects the formation of the neural tube. abnormalities reduced 70% of time. there is also a certain degree of weight gain that is beneficial, which can depend on the weight of the mother at the start of pregnancy. around 25-30 pounds. malnutrition can cause huge issues for cognitive development, esp during third trimester.

are parents of newborns exhausted because newborns sleep so little?

parents of newborns are not exhausted because newborns sleep little, but because they sleep a lot (16-18 hrs) in short durations -- around a couple hours at a time. they also frequently wake up for various reasons. actually, if babies sleep for more than a few hours at a time, parents are advised to wake them up for a feeding.

soothing crying infants

parents vary widely in responsiveness to crying. parents high in empathy and with child-centered attitudes more likely to respond quickly and sensitively. common technique is lifting baby to shoulder and rocking or walking around with them, and also swaddling.

implantation

part of the germinal period. blastocyst buries into uterine lining, and trophoblast multiples quickly to form amnion (cushions against movements by mother). yolk sac also emerges, producing blood cells until developing liver, spleen, and bone marrow are mature enough to take over this function. as many as 30% zygotes don't survive this period.

emotional stress and prenatal care

severe emotional stress during pregnancy can expose baby to a variety of defects and problems. possibly due to response of stress hormones moving blood away from the uterus. hormones can also cross placenta and cause dramatic rise in fetal stress hormones, fetal HR, blood glucose, and activity level. leads to susceptibility to later illness, and associated with behavioral problems. reduced strongly with social support.

sleep training

sleep training is controversial; there are different levels and extremes. the goal is to have the baby learning how to soothe themselves to sleep. still quite subjective, because the lives of parents and the needs of infants are individual and different.

tobacco and teratogens

smoking associated with low birth weight, miscarriage, impaired heart rate and breathing, prematurity, blood vessel abnormalities, and death. likelihood of asthma and cancer in childhood also increase. also more often have colic, persistent crying. shorter attention spans, impulsivity and overactivity, lower intelligence scores, etc. nicotine constricts blood vessels and lessens blood flow to uterus, raising concentration of carbon monoxide in bloodstream and reducing transfer of nutrients.

prescription and nonprescription drugs and teratogens

thalidomide, taken 4-6 weeks after conception, produces gross deformities of developing arms and legs and sometimes organs. can affect later intelligence scores. current most widely used is vitamin A derivative isotretinoin, which treats severe acne. exposure during first trimester results in eye, ear, skull, brain, heart, and immune system abnormalities. any drug with molecules small enough to penetrate placenta can enter embryo's blood stream. even aspirin, high doses of caffeine, and persistent intake of antidepressants can cause harm.

the placenta and umbilical cord

the formation of these structures occurs during the germinal period. chorion surrounds the amnion, and villi form along with placenta. placenta permits food and O2 to reach developing organism and waste to be carried away without directly mixing mother's and organism's blood. placenta connected to organism by umbilical cord, which grows to 1-3 ft over course of pregnancy. contains one large vein that delivers blood with nutrients, and two arteries to remove waste. force of blood flowing through keeps it firm so it doesn't tangle.

embryonic period

the second period of pregnancy. lasts from plantation through 8th week, during which groundwork is laid for all body structures and internal organs.

maternal age

there is a sharp rise in complications in women ages 50-55, an age at which, because of menopause, few women can conceive naturally.

barriers to prenatal care

these barriers can be real or perceived. 1) insufficient skilled providers (midwives, nurses, doctors) 2) travel (physical access to clinics & hospitals) 3) cost 4) knowledge of important prenatal care methods 5) cultural barriers (ex., women in certain areas cannot be treated by men) 6) food access

fetal period

third period of pregnancy. from 9th week until the end. longest prenatal period during which organism increases rapidly in size.

vision

this is the least developed of the newborn's senses, as their visual structures are not fully formed. the cells in the retina which transform light into messages for the brain are not as mature or packed together as they will be in several months. optic nerve that relays messages and visual centers in brain that receive them will not be adultlike for several years. additionally, the muscles of the lens which permit us to adjust visual focus to varying distances are weak. as they cannot focus eyes well, visual acuity (fineness of discrimination) is limited. see unclearly across wide range of distances. prefer to look at colored stimuli, but not good at distinguishing between them until 4 months. still, newborns actively explore visual world by scanning for interesting sights and tracking moving objects.

rooting reflex

this reflex happens when something touches the baby's cheek, and the baby turns toward the feeling with an open mouth. helps them find an appropriate food source and facilitates sucking.

grasping reflex

this reflex happens when something touches the baby's palm, and the baby grasps at it. this has the consequence of facilitating caregiver bonding, and helps with their ability to grasp onto things later.

stepping reflex

this reflex helps form the basis for later walking. it goes away ~2 months, but the baby will still perform it sometimes, such as when they are picked up and are in midair. it only seems to go away because the legs become too heavy to lift with increased fat and weak muscles. if stepping not practiced, babies won't start walking quite as early.

moro reflex

this reflex occurs when the infant feels it is experiencing a falling sensation and quickly spreads out its arms and legs, then brings them back in. there is a survival instinct to this; makes it easier for the baby to grasp onto an adult to save themselves, and maintain hold. babies also do this in response to being startled.

preventative healthcare in infants

thoughts around vaccines are influenced by social norms; however, they are an important part of preventative healthcare. too many opt-outs weaken herd immunity and result in more deaths from preventative diseases. there are not just independent effects of getting a vaccine; they affect other people as well. the more people have them, the less diseases will spread among the non-immunized. this population might include very young infants, who are unable to get certain types of shots. the autism myth has led some rates of vaccination to go down, leading to increased outbreaks (such as with measles and whooping cough).

states of arousal

throughout day and night, infants move in and out of five states of arousal, degrees of sleep and wakefulness. striking individual differences exist, and babies who spend more time alert probably get more social stimulation and opportunities to explore the world, giving them cognitive advantages.

touch

touch helps stimulate early physical growth. it is also vital for emotional development. sensitivity to touch is well developed at birth, and newborns use touch to investigate their world. can distinguish shape of small objects and texture, evidenced by tendency to hold longer onto unfamiliar objects. also highly sensitive to pain at birth. smell of milk of the baby's mother reduces distress associated with pain more effectively than odor of other's milk or of formula. physical touch like in gentle holding also releases endorphins, painkilling chemicals in the brain. allowing baby to endure severe pain overwhelms the nervous system with stress hormones. result is heightened pain sensitivity, sleep disturbances, feeding problems, and difficulty calming down when upset.

fetal alcohol syndrome

typical diagnosis from group of alcohol related disorders that have problematic prenatal effects. this one is typical when a mother drinks heavily during pregnancy. associated with slow physical growth, facial abnormalities (short eyelid openings, thin upper lip, smooth philtrum), brain injury resulting in impairment in at least 3 areas of functioning, and possible other defects. even babies provided extra nutrients fail to catch up to peers in growth. alcohol interferes with production and migration of neurons in neural tube, leading to reduced brain size and abnormalities in structure and functioning. widespread epigenetic changes, including altered methylation of many genes.

Rh factory incompatibility

when inherited blood types of the mother and fetus differ, serious problems sometimes result. Rh factor incompatibility occurs when mother is Rh negative, and the baby inherits its father's Rh positive blood type. if even a little bit of the blood crosses the placenta, the mother's immune system reacts. antibodies formed can enter the fetus's system, destroying its RBCs and reducing the O2 supply to its organs and tissues. firstborns are often not affected by this, but later pregnancies may be.

are infants born with food preferences?

yes, because the mother's diet affects the amniotic fluid, babies are born with preferences for foods from their own cultures.

are newborns better able to distinguish sounds from their own language?

yes, newborns are better able to distinguish sounds from their own language than from other languages.