Chapter 3 - Prenatal Development

Question 1

Prenatal Development

Answer 1

Prenatal development begins with conception The ovum is 1/175 inch, the largest cell in the human body Sperm cells are much smaller, 1/500 inch

Question 2

Advantages and Disadvantages of parenthood mentioned by American Couples

Answer 2

Advantages • Giving and receiving affection • Experiencing the stimulation and fun that children add • Being accepted as a responsible and mature member of the community • Experiencing new growth and learning opportunities • Having someone to carry on to after ones death • Gaining a sense of accomplishment and creativity from helping children grow • Having someone to provide care in old age • Learning to be less selfish and to sacrifice • Help with work or add to income to family resources Disadvantages • Loss of freedom • Financial strain • Family work conflict • Interference with moms employment or career progress • Worries over children’s health, safety, wellbeing • Risks of the world • Reduced time with partner • Loss of privacy • Fear of children turning out badly, through no fault of their own

Question 3

Ovulation and Menstruation

Answer 3

About once every 28 days, an ovum is released from one of the ovaries, and begins to travel down a fallopian tube The corpus luteum secretes hormones that will prepare the uterine lining for implantation If pregnancy doesn’t occur, the corpus luteum shrinks, and the uterine lining is discarded

Question 4

Sperm

Answer 4

On average, males produce about 300 million sperm per day During intercourse, sperm cells are released, and swim through the cervix and into the fallopian tube Only 300 to 500 sperm cells will reach the ovum, if one is present at the time of intercourse Or soon afterwards; sperm cells live for about 6 days Usually, fertilization occurs either the day of ovulation or in the 2 days afterwards

Question 5

Prenatal development three phases

Answer 5

The period of the zygote The period of the embryo The period of the fetus

Question 6

The Period of the Zygote

Answer 6

Lasts from conception until implantation is complete, approximately 2 weeks The zygote duplicates while travelling down the fallopian tube The first duplication takes about 30 hours, after which cell duplication speeds up considerably A yolk sac forms; this will produce blood cells until the liver, spleen, and bone marrow are mature enough to produce their own Note that perhaps as many as 30% of zygotes do not survive these first 2 weeks

Question 7

Blastocyst

Answer 7

the zygote 4 days after fertilization, when the tiny mass of cells forms a hollow, fluid-filled ball

Question 8

Embryonic disk

Answer 8

a small cluster of cells on the inside of the blastocyst, from which the new organism will develop

Question 9

Trophoblast

Answer 9

the thin outer ring of cells of the blastocyst, which will become the structures that provide protective covering and nourishment to the new organism

Question 10

Implantation

Answer 10

attachment of the blastocyst to the uterine lining, which occurs 7 to 9 days after fertilization The trophoblast multiplies quickly after implantation begins, forming the amnion and chorion

Question 11

Amnion

Answer 11

the inner membrane that encloses the prenatal organism develops from the Trophoblast

Question 12

Amniotic fluid

Answer 12

the fluid that fills the amnion, helping to keep temperature constant and to provide a cushion against jolts caused by the mother’s movement

Question 13

Chorion

Answer 13

develops from the Trophoblast it is the outer membrane that surrounds the amnion and sends out tiny, fingerlike villi, from which the placenta begins to develop These are the villi that are sampled in chorionic villus sampling

Question 14

Placenta

Answer 14

the organ that permits exchange of nutrients and waste products between the bloodstreams of the mother and the embryo, while also preventing the mother’s and embryo’s blood from mixing directly

Question 15

Umbilical cord

Answer 15

Umbilical cord - the long cord that connects the prenatal organism to the placenta, delivering nutrients and removing waste products This cord grows to a length of 1-3 feet One large vein delivers nutrient-rich blood to Baby Two arteries remove Baby’s waste products The constant flow of blood keeps the cord firm, so it rarely tangles with Baby’s movements

Question 16

The Period of the Embryo

Answer 16

Embryo - the developing organism from the third week, when implantation is complete, through the eighth week after conception Initially only about the size of an apple seed, but all major internal and external structures form during this period

Question 17

The Period of the Embryo Week 3

Answer 17

Week 3, the inner cell mass differentiates into three layers 1. Endodermal: internal organs and glands 2. Ectodermal: the parts of the body that maintain contact with the outside world—the nervous system; the sensory parts of the eyes, nose, and ears; skin; hair 3. Mesodermal: muscles, cartilage, bone, sex organs, and heart The ectoderm folds over to form the neural tube. At 3 ½ weeks the brain starts to develop from the neural tube

Question 18

The Period of the Embryo week 4

Answer 18

Beginning of week 4, the embryo looks like a tiny tube By the end of week 4, it assumes a curved form, with a bump below the head (a primitive heart) and tiny buds that will become the limbs

Question 19

The Period of the Embryo 5th week

Answer 19

In the 5th week, the head and brain develop rapidly The upper limbs form The lower limbs appear and look like small paddles

Question 20

The Period of the Embryo 6th week

Answer 20

In the 6th week, the head continues to grow rapidly Differentiation of the limbs occurs as elbows, fingers, and wrists become recognizable The ears and eyes are discernable

Question 21

The Period of the Embryo week 7

Answer 21

the limbs develop rapidly Stumps appear that will form fingers and toes

Question 22

The Period of the Embryo week 8,

Answer 22

By the end of week 8, the embryo has distinctly human features Almost half of the embryo consists of the head The eyes, ears, toes, and fingers are easily distinguishable All internal and external structures have formed

Question 23

The Period of the Fetus

Answer 23

Fetus - the developing organism from the 9th week to the 38th week after conception During this period, we see mostly Further development of the already formed organ structures Increases in size and weight At the beginning of this period, the fetus weighs less than an ounce and measures about 5 cm in length By birth, about 266 days after conception, most weight 3 to 3.5 kg and measure about 51 cm in length Fetal growth begins to slow around the eighth month Appearance changes drastically during the fetal period The head grows less than the other parts of the body The head’s ratio decreases from 50% of the body mass at 12 weeks to 25% at birth By 6 to 7 months of age, the fetus has a chance of survival outside of Mom’s body This process isn’t complete until 9 months

Question 24

First trimester 9 weeks to 3 months

Answer 24

The organs, muscles and nervous system start to become organized and developed Facial features become more human looking as the eyes move from the sides of the head to the front Fetal activity begins in the 3rd month, when the fetus is capable of forming a fist and wiggling toes Mom can’t feel this yet The fetus appears to become sensitive to environmental stimulation by this point—it moves its whole body in response to a touch stimulus The skin is transparent until the 3rd month, when it begins to thicken By 3 months, the brain is organized into functional subdivisions—seeing, hearing, thinking, etc Sexual development becomes apparent by the end of the 3rd month The eyelids seal shut near the beginning of the 3rd month, and stay that way for 3 months

Question 25

Second trimester 4 months

Answer 25

By the 4th month, the eyes are sensitive to light through the lids Finger and toe nails appear by the 4th month, as do pads that will have the fingerprints Head hair begins to grow

Question 26

Second trimester 5 months

Answer 26

By the 5th month, a loud noise may activate the fetus During this month, the fetus swims effortlessly The fetus is now capable of kicking and turning It may also begin to display rhythms of sleep and activity By about 17-20 weeks, the fetus has developed vernix and lanugo

Question 27

Second trimester 6 months

Answer 27

By 6 months, a bone structure begins to support a more erect posture

Question 28

third trimester 7 months

Answer 28

By the 7th month, brain connections are sufficient for the fetus to exhibit a sucking reflex when the lips are touched A baby born after only 7 months will need to be provided with extra oxygen, will have to take food in very small amounts, and will have to live for several weeks in an incubator for temperature control

Question 29

third trimester 8 months

Answer 29

In the 8th month, fat appears under the skin to help regulate body temperature A baby born at 8 months is susceptible to infection Beginning in the 8th month, Mom’s body contributes disease-fighting antibodies to the fetus, developed through her own exposure to foreign bodies

Question 30

vernix and lanugo

Answer 30

Vernix – white cheese like substance that protects the skin from chapping in the amniotic fluid Lanugo – also appears around the body helping the vernix

Question 31

Age of viability

Answer 31

the age at which the infant has a chance to survive if born prematurely Currently, the age of viability is about 23 to 24 weeks

Question 32

Premature birth

Answer 32

The major obstacle for a premature baby is the immaturity of the air sacs of the lungs A baby born very prematurely will also not be able to digest food Fat will not yet have formed under the skin to assist in temperature regulation

Question 33

fetal differences

Answer 33

Some precursors of later individual differences become evident shortly before birth For instance, fetuses that are more active in the womb tend to be more active and less fearful at 2 years of age These fetal differences aren’t consist enough to reliably predict later differences, though

Question 34

Teratogen

Answer 34

any environmental agent that causes damage during the prenatal period The impact of a teratogen is influenced by • Dose • Timing/ age (The embryonic period is when damage is most likely to occur. During the fetal period it is usually minor) • Heredity • Other negative influences (nutrition, presence of other teratogens)

Question 35

Thalidomide

Answer 35

was widely marketed to pregnant women in the 1960s Depending on timing of exposure, babies were born with malformation s of the eyes and ears, deformations of the internal organs, or fused fingers and toes, or (most famously) phocomelia

Question 36

Diethylstilbestrol (DES)

Answer 36

Prenatal medication meant to prevent miscarriage. 1945-1970 Synthetic hormone Daughters of mothers who used this showed abnormally high rates of cancer of the vagina, infertility, malformation of the uterus, miscarriages and premature birth once they reached adolescence and young adulthood. Sons showed increased rate of genital abnormallies and cancer of the testes

Question 37

Aspirin use during pregnancy

Answer 37

Possibly causes • Low birth weight • Infant death • Poor motor development • Lower intelligent scores in early childhood

Question 38

Caffeine use during pregnancy

Answer 38

More then 100mg a day Low birth weight Miscarriage chances increase

Question 39

Antidepressant use during pregnancy

Answer 39

Premature delivery Birth complications including –respiratory distress – persistent high blood pressure in infancy

Question 40

Illegal drugs during pregnancy

Answer 40

At risk for - Prematurity - Low birth weight - Physical defects - Breathing dificultys - Death soon after birth If born addicted - Feverish - Irritable - Trouble sleeping - Shrill cries - Less attentive to their environment - Slow motor development - Can normalize after infancy

Question 41

Tobacco use during pregnancy

Answer 41

It constricts blood vessels in the mother that lessons blood flow to the uterus and causes abnormal placenta growth. This reduces nutrient availability to the fetus. Quitting at any time during pregnancy helps. - Low birth weight (best known affect) - Miscarriage - Premature birth - Impaired heart rate and breathing during sleep - Infant death - Asthma - Cancer - Behavioral abnormallies - ADHD symptoms “passive smokers” – lots of second hand smoke

Question 42

Effects of Alcohol on prenatal development

Answer 42

In Canada and the US, this is the most widely used drug that is known to harm the fetus Almost 15% of Canadian mothers report consuming some amount of alcohol during the pregnancy Prenatal alcohol exposure is the leading cause of developmental disability among children in Canada and in the rest of the Western world The withdrawal effects in newborns of mothers who drink heavily are similar to those in newborns whose mothers are drug addicted

Question 43

Fetal Alcohol Spectrum Disorder (FASD)

Answer 43

a range of physical, mental, and behavioural outcomes caused by prenatal alcohol exposure This is divided into three categories 1. Fetal Alcohol Syndrome (FAS) 2. Partial Fetal Alcohol Syndrome (P-FAS) 3. Alcohol-Related Neurodevelopmental Disorder (ARND)

Question 44

Fetal Alcohol Syndrome (FAS)

Answer 44

the most severe form for FASD, distinguished by slow physical growth, facial abnormalities, and brain injury; usually seen in children whose mothers consumed large amounts of alcohol during most or all of pregnancy Diagnosed when there is a) slow physical growth b) a pattern of three facial abnormalities: short eyelid openings, thin upper lip, a smooth or flattened philtrum, c) brain injury, evident in a small head and impairment in at least three areas of functioning, such as memory, language, attention span, activity level, planning, motor coordination, social skills Defects of the eyes, ears, nose, throat, heart, genitals, urinary tract, or immune system may also be present

Question 45

Partial Fetal Alcohol Syndrome (P-FAS)

Answer 45

a form of FASD characterized by facial abnormalities and brain injury, but less severe than FAS; usually seen in children whose mothers drank alcohol in smaller quantities during pregnancy Diagnosed when we see a) two of the three facial abnormalities and b) brain injury, evident in at least three areas of impairment

Question 46

Alcohol-Related Neurodevelopmental Disorder (ARND)

Answer 46

the least severe form of FASD, involving brain injury, but with typical physical growth and absence of facial abnormalities

Question 47

How does Fetal Alcohol Spectrum Disorder (FASD) occur?

Answer 47

Alcohol interferes with cell duplication and migration in the neural tube We see arrested brain growth, structural damage, and abnormalities in the electrical and chemical activity of the brain Also, it takes a lot of oxygen to metabolize alcohol, leaving less oxygen for the developing Baby Note that even one drink per day is associated with reduced head size and body growth, even into adolescence

Question 48

Radiation

Answer 48

• Miscarriage with underdeveloped brains - Physical deformities - Slow physical growth - Increased chance of cancer - Abnormal brain wave activity - Low intelligence test scores - Language disorders - Emotional disorders

Question 49

Environmental pollution

Answer 49

Babies are born with pollutants in their system already. Possible effects Impair prenatal development Increases chances of life threatening diseases Mercury – impared speech, mental retardation, physical deformitys, difficulty chewing and swallowing, uncoordinated movment. Avoid long lived fish during pregnancy because of risk of mercury Polychlorinated Biphenyls (PBC’s) – used to insulate electrical equipment. Causes: low birth weight, discoloured skin, deformities in the gums and nails, brain wave abnormallys, delayed cognitive development Lead – premature birth, low birth weight, brain damage, physical defects, lower mental and motor development Dioxins – toxins resulting from incineration – linked to brain, immune system, and thyroid damage, breast and uterine cancer, sex ratio of births (2 time as many girls from an effected father)

Question 50

Rubella

Answer 50

This virus can damage the central nervous system of the fetus, resulting in blindness, deafness, and developmental disability The heart, liver, and bone structure may also be damaged, depending on the timing of infection Affects only 2-3% of offspring of mothers infected within 2 weeks after their last period, 50% of offspring when the infection is in the first month following conception, 22% when it occurs during the second month, 6-8% when it’s during the 3rd, and very low incidence thereafter

Question 51

HIV

Answer 51

This virus is transmitted through body fluids, and can be transmitted from mother to fetus through the placenta, from mother to baby during the birth process, or from mother to baby through breast milk HIV can act as a teratogen Some infected babies are born with facial deformities Larger-than-normal eye separation Boxlike foreheads Flattened nose bridges Misshapen eye openings Babies who get AIDs and are untreated have a 50% chance of dying by 1 and 90% chance of dying by 3.

Question 52

Herpes

Answer 52

Types Cytomegalovirus –most frequent prenatal infection, transmission through repertory or sexual contact often with out symptoms. Herpes simplex 2 – sexually transmitted, especially dangerous,

Question 53

Toxoplasmosis

Answer 53

a parasitic disease caused by eating raw or undercooked meat or through contact with the feces of infected cats; during the first trimester, it leads to eye and brain damage In the second and third trimesters, it’s linked to mild visual and cognitive impairments About 80% of affected newborns with no obvious signs do develop disabilities later in life In an adult, the symptoms resemble a cold, so a person can contract toxoplasmosis and never realize it

Question 54

Exercise

Answer 54

In healthy, physically fit women, regular moderate exercise is related to increased birth weight So walking, swimming, biking, aerobic workouts = good Very frequent, vigorous, extended exercise results in lower birth weight than in healthy controls So working up a sweat for more than 30 minutes, 4 or 5 days a week, especially in the third trimester = bad During the third trimester, mothers may have to cut back on exercise Note, however, that most women don’t engage in enough moderate exercise during pregnancy to promote their own and their baby’s health Keeping fit reduced physical discomforts, like back pain and upward pressure on the chest Pregnant women with health problems should consult with doctors about fitness routines

Question 55

Nutrition

Answer 55

Consider the increase in both size and number of cells during prenatal development The quality of Mom’s diet, during and before pregnancy, is paramount for Baby’s nutrition Mother should gradually increase calories during pregnancy. 10 extra calories a day in first trimester, 265 in second, 430 in third. Resulting in a weight gain of 25 – 30 pounds. Maternal malnutrition is often confounded with inadequate housing and health care, inferior education and sanitation, and the daily stress of poverty This makes it difficult to isolate the effects of malnutrition from other factors Using a prenatal multivitamin supplement can provide protection against a number of birth defects

Question 56

Prenatal Malnutrition

Answer 56

Malnutrition can occur even when there is enough food consumption, if it’s not the right kinds of foods First trimester of malnutrition in the most likely to result in miscarriage or physical deformities. Third trimester malnutrition results in lower brain weight because the brain is developing during this time. Can cause serious damage to the central nervous system of the baby. Protein deficits can produce damage to the kidneys and intestines, and disrupt skeletal growth in the fetus Suppresses development of the immune system and can make the infant more susceptible to respiratory illness. Infants can be irritable and unresponsive to stimulation and have a high pitched cry. Low intake of certain vitamins can affect the eyes and internal organs and increase the number of malformations The intellectual abilities of babies who suffered prenatal malnutrition depend in large part on their childhood environments

Question 57

Infant Malnutrition

Answer 57

Babies who are malnourished both prenatally and postnatally are more likely to show delayed motor and social development They become relatively inattentive, unresponsive, and apathetic Poverty-stricken babies whose diets are supplemented are more advanced in motor development and more socially interactive and energetic Children who were malnourished prenatally but have adequate diet and stimulation in infancy and childhood tend to show no long-term intellectual deficit An enriched home environment may compensate for many of the effects of malnutrition The outcome also depends on the timing and severity of the malnutrition, though

Question 58

Effects of maternal malnutrition can include

Answer 58

• Brain weight up to 1/3 less than expected • Deficits of between 6 and 25% in the size of major internal organs • Increased rates of spontaneous abortion and infant death • Increased rates of congenital defects • Low birth weight • Prematurity • Increased rates of schizophrenia later in life

Question 59

Stress

Answer 59

Miscarriage, premature birth, low birth weight Digestive illnesses colic Newborn irritability Feeding and sleep problems during infancy Behavioural problems at age 4 Heightened probability of congenital physical anomalies, such as heart defects and cleft palate

Question 60

There are confounds in the research between maternal anxiety during pregnancy and some later child outcomes

Answer 60

Confounds - Reports of stress are usually collected postnatally - Can’t separate prenatal from postnatal influences - Mom and baby are also genetically related It’s unlikely that the confounds could account for all of the effects we see in babies whose mothers experience significant prenatal stress - Some effects of maternal stress are evident during the prenatal period—low birth weight and problems during delivery couldn’t be due to the postnatal environment - Children born to mothers who were pregnant during large-scale disasters often show poorer intellectual and language abilities in childhood

Question 61

When is stress not predictive of negative outcomes

Answer 61

When stress is within normal limits, it’s not predictive of negative outcomes Particularly if Mom is well-nourished, financially stable, and carrying wanted pregnancies Social support is important here as well, and makes negative outcomes much less likely

Question 62

Blood Incompatibility

Answer 62

Rh factor incompatibility can occur if Mom is Rh-negative and Dad is Rh-positive If any of Baby’s Rh-positive blood crosses the placenta, Mom begins to build antibodies Since antibodies take time to form, the first child is rarely affected There is a vaccine, as long as you know to take it

Question 63

Parental Age

Answer 63

The optimal time for childbearing has traditionally been considered to be between the ages of 20 and 34, with 25-29 as the best time within this range Births to mothers over 35 or under 20 are sometimes considered a cause for concern

Question 64

Achondroplasia

Answer 64

Achondroplasia is an age-related mutation in the father’s sperm that becomes dominant in the child who inherits it Dad’s age is important contributor because of mutation in the father’s sperm. The most obvious characteristics are dwarfism and a large head, with a prominent forehead and a depressed bridge of the nose

Question 65

Increased maternal age

Answer 65

Increased maternal age is associated with an increased likelihood of giving birth to a baby with Down syndrome The relative frequency of mutation in the father’s sperm increases with age as well Dad’s age may also be an important contributor to autistic disorder Some studies say older Moms are at risk for preterm birth, difficulties during delivery, and both infant and maternal mortality More the case 2 or 3 decades ago than now Older Moms are more educated now, and thus more likely to seek early prenatal care and to be in good health When Mom’s health is good, being older seems to carry only minimal risk

Question 66

teen Moms

Answer 66

Babies of teen Moms are at greater than average risk Increased risk of complications during pregnancy, preterm birth, and low birth weight This may be largely because of Inadequate prenatal care More risky health behaviours Stress

Question 67

Nurse-Family Partnership

Answer 67

A voluntary home visit program for first time, low income, expectant mothers. Visits happened 7 times during pregnancy, once a month for the first two years after birth Goals: reduce birth complications, promote competent parenting, improve family conditions Results: higher language and intelligence scores, better academic achievement, less behavior problems, fewer subsequent births, more contact with the father, less welfare dependence, less parental stress,

Question 68

Preeclampsia (toxemia)

Answer 68

Blood pressure increases sharply in the face, hands, and feet in the second half of pregnancy. If untreated it can cause convulsions in the mother and fetal death.

Question 69

Why mothers might not seek prenatal care

Answer 69

Situational barriers – difficulty finding a doc, transportation, ext. Personal barriers – stress, lack of knowledge, family demands

Question 70

Prenatal Iron deficiency and memory in infants

Answer 70

• Diabetes buts the baby at risk for birth defects during early pregnancy and unusually large babies in late pregnancy - In this case the baby needs a lot iron. They will use their bodies own stores. This can cause a decline in brain activity and damage the development of the hippocampus. - They can score lower in intelligence in childhood - This is due to memory impairment

Question 71

Dos of healthy pregnancy

Answer 71

• Make sure you have been vaccinated before pregnancy - See a doctor as soon as you suspect pregnancy and go for regular appointments throughout pregnancy - Eat well balanced meals, take supplements before and during pregnancy, and eat the appropriate amount of calories - Obtain literature from your doctor, library, bookstore - Keep physically fit - Avoid emotional stress - Get plenty of rest - Enrol in prenatal and childbirth class with your partner

Question 72

Don’ts of health pregnancy

Answer 72

• Don’t take drugs (even legal ones) without talking to your doc - Don’t smoke or expose yourself to second hand smoke - Don’t drink alcohol - Don’t engage in activities that would expose you to chemicals or radiation - Don’t expose your baby to harmful infectious diseases - Don’t go on a diet - Don’t gain too much weight

Question 73

What percentage of U.S. married couples bear children today?

Answer 73

70 percent

Question 74

Currently, the average number of children per couple in the United States and Canada is

Answer 74

1.8

Question 75

During the period of the zygote, the cluster of cells on the inside of the blastocyst form the

Answer 75

embryonic disk, which becomes the new organism.

Question 76

After tiny blood vessels emerge and burrow into the uterine wall,

Answer 76

the developing placenta permits food and oxygen to reach the developing organism and waste products to be carried away.

Question 77

During the final trimester, the fetus’s brain continues to grow, although

Answer 77

the head does not become too large to pass through the birth canal.

Question 78

The connection between low birth weight and cardiovascular disease was found to be strongest for

Answer 78

people whose weight-to-length ratio at birth was very low.

Question 79

Commonly used as a sedative during the early 1960s, thalidomide caused

Answer 79

gross deformities of the embryo’s developing arms and legs.

Question 80

Babies who are prenatally exposed to cocaine, heroin, or methadone are at risk for

Answer 80

low birth weight, physical defects, breathing difficulties, and death around the time of birth.

Question 81

What percentage of U.S. women smoke during pregnancy

Answer 81

14 percent

Question 82

The most severe form of fetal alcohol spectrum disorder (FASD), usually seen in children whose mothers consumed large amounts of alcohol during most or all of pregnancy, is distinguished by

Answer 82

slow physical growth, facial abnormalities, and brain injury.

Question 83

Low-level radiation exposure, such as from medical X-rays, can

Answer 83

increase the risk of childhood cancer.

Question 84

High levels of prenatal mercury exposure can cause

Answer 84

widespread brain damage.

Question 85

Abnormalities resulting from prenatal rubella increase

Answer 85

the risk of severe mental illness

Question 86

Keri just discovered that she’s pregnant and asks you what vitamins she should start taking. Which of the following vitamin-mineral supplements helps to prevent abnormalities of the neural tube, including anencephaly and spinal bifida?

Answer 86

folic acid

Question 87

Toxemia, also known as preeclampsia, is a complication during pregnancy that can cause the woman to experience

Answer 87

a sharp increase in blood pressure and swelling of the face, hands, and feet.

Question 88

As a result of ________ in critical brain areas, a diabetic pregnancy places the fetus at risk for long-term academic difficulties

Answer 88

iron depletion

Question 89

Group prenatal care is an effective intervention for

Answer 89

minority expectant mothers.

Question 90

For most expectant parents, the prenatal period is a period of

Answer 90

major life change accompanied by excitement.

Question 91

The most important element in preparing for parenthood is a

Answer 91

close relationship between the expectant parents.

Question 92

First Trimester The period of the embryo 3-8 weeks

Answer 92

Week 3, the inner cell mass differentiates into three layers The ectoderm folds over to form the neural tube. At 3 ½ weeks the brain starts to develop from the neural tube Beginning of week 4, the embryo looks like a tiny tube By the end of week 4, it assumes a curved form, with a bump below the head (a primitive heart) and tiny buds that will become the limbs In the 5th week, the head and brain develop rapidly The upper limbs form The lower limbs appear and look like small paddles In the 6th week, the head continues to grow rapidly Differentiation of the limbs occurs as elbows, fingers, and wrists become recognizable The ears and eyes are discernable the limbs develop rapidly Stumps appear that will form fingers and toes By the end of week 8, the embryo has distinctly human features Almost half of the embryo consists of the head The eyes, ears, toes, and fingers are easily distinguishable All internal and external structures have formed

Question 93

First Trimester The period of the fetus first trimester 9 weeks to 3 months

Answer 93

The organs, muscles and nervous system start to become organized and developed Facial features become more human looking as the eyes move from the sides of the head to the front Fetal activity begins in the 3rd month, when the fetus is capable of forming a fist and wiggling toes Mom can’t feel this yet The fetus appears to become sensitive to environmental stimulation by this point—it moves its whole body in response to a touch stimulus The skin is transparent until the 3rd month, when it begins to thicken By 3 months, the brain is organized into functional subdivisions—seeing, hearing, thinking, etc Sexual development becomes apparent by the end of the 3rd month The eyelids seal shut near the beginning of the 3rd month, and stay that way for 3 months

Question 94

First Trimester 3 Peirods

Answer 94

Conception – 3 months The period of the zygote 2 weeks The period of the embryo 3-8 weeks The period of the fetus first trimester 9 weeks to 3 months

Question 95

Second Trimester

Answer 95

3-6 months – period of the fetus By the 4th month, the eyes are sensitive to light through the lids Finger and toe nails appear by the 4th month, as do pads that will have the fingerprints Head hair begins to grow By the 5th month, a loud noise may activate the fetus During this month, the fetus swims effortlessly The fetus is now capable of kicking and turning It may also begin to display rhythms of sleep and activity By about 17-20 weeks, the fetus has developed vernix and lanugo By 6 months, a bone structure begins to support a more erect posture Further development of the already formed organ structures Increases in size and weight Appearance changes drastically during the fetal period The head grows less than the other parts of the body

Question 96

Third Trimester

Answer 96

6-9 month – Period of the fetus By the 7th month, brain connections are sufficient for the fetus to exhibit a sucking reflex when the lips are touched A baby born after only 7 months will need to be provided with extra oxygen, will have to take food in very small amounts, and will have to live for several weeks in an incubator for temperature control In the 8th month, fat appears under the skin to help regulate body temperature A baby born at 8 months is susceptible to infection Beginning in the 8th month, Mom’s body contributes disease-fighting antibodies to the fetus, developed through her own exposure to foreign bodies By 6 to 7 months of age, the fetus has a chance of survival outside of Mom’s body By birth, about 266 days after conception, most weight 3 to 3.5 kg and measure about 51 cm in length Fetal growth begins to slow around the eighth month This process isn’t complete until 9 months

Question 97

Effects of Some Infectious Diseases During Pregnancy TABLE 1

Answer 97

Question 98

Female Reproductive Organs and Fertilization DIAGRAM

Answer 98

Question 99

First Trimester DIAGRAM

Answer 99

Question 100

Second and Third DIAGRAM

Answer 100

Question 101

Prenatal diagnosis Methods TABLE

Answer 101

Question 102

Sensitive Periods in Prenatal Development DIAGRAM

Answer 102

Question 103

Sex Cell Creation DIAGRAM

Answer 103

Question 104

Uterus and Placenta DIAGRAM

Answer 104

Question 105

Fetal Alcohol Spectrum Disorder Criteria TABLE

Answer 105

Question 106

Congenital

Answer 106

Means present from birth