Section 3
Section 3
Childbirth
Childbirth
Objectives
Objectives
Before class begins, write the objectives
on the board. Have students copy the
objectives into their notebooks at the
start of class.
1. Focus
Warm-Up Health Stats
䊳
Identify the three stages
of the birth process.
䊳
Describe four
complicating factors that
may arise at birth.
Vocabulary
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12.1%
When Mothers
Smoked
The Birth Process
As the baby’s due date approaches, the mother and father prepare. Most
couples choose to have their baby in a hospital, where obstetricians,
specially trained nurses, and medical equipment are available should
something go wrong. If the pregnancy has gone well and the mother is in
good health, a couple may choose to have the baby at home or at a
home-like setting with the help of a certified nurse-midwife. A
certified nurse-midwife is a nurse who is trained to deliver babies.
Near the end of the ninth month of pregnancy, the head of the fetus
moves lower in the uterus. The birth process begins when the muscular
walls of the uterus begin a series of contractions that will push the fetus
out of the mother. Birth takes place in three stages—labor, delivery of
the baby, and delivery of the afterbirth. Refer to Figure 6 to see what
happens during each stage.
Connect to
YOUR LIFE
498
Chapter 19
7.5%
Propose a plan that could help decrease the
number of pregnant women who smoke.
Connect to Sample answer: excitement
YOUR LIFE and anxiety
498
Percentage of Babies
With Low Birthweight
When Mothers
Didn’t Smoke
Teaching Transparency W67
Sensitive Issues
the risk for low birthweight?
certified nurse-midwife
labor
postpartum period
stillbirth
cesarean section
premature birth
low birthweight
multiple birth
Direct students to compare the two
pie charts. Ask: What effect does
cigarette smoking during pregnancy
have on a baby’s weight? (The
baby is more likely to have a low
birthweight.) Point out that low
birthweight can be harmful to the
newborn, and that they will learn
more about the health risks to low
birthweight babies in this section.
After students finish writing, invite
them to share their ideas for convincing women to stop smoking during
pregnancy.
The childbirth process is a sensitive
subject to many students because of
its association with female reproductive anatomy. Focus on the processes
of childbirth. Maintain a clinical tone
throughout all discussions of the birth
process.
Health Stats How does smoking during pregnancy affect
What mix of emotions might expectant parents
feel during the birth process?
Chapter 19
and Health
L3 Graphing
Instruct students to make a pie graph that
shows the relative time each stage of
childbirth typically lasts. Students can use
the approximate times for each stage
given in the text. Suggest that students
calculate an average time based on the
time ranges given to determine a total
time for the process. Then students can
use these averages to calculate the percent
of total time that each stage requires.
2. Teach
FIGURE 6 The three stages of
birth include labor, delivery of the
baby, and delivery of the afterbirth.
Vagina
1 Labor The work performed by the mother’s body
to push the fetus out is called labor. Labor for a first
child may last from about 2 to 24 hours or longer. During
this stage, strong contractions of the muscles of the
uterus cause the cervix to increase in width, or dilate.
Each contraction typically lasts from 30 to 90 seconds. At first, the contractions may be minutes apart, but
by the end of labor, they are usually only a few seconds
apart. Near the end of this first stage, the amniotic sac
breaks, and the cervix becomes softer and wide enough
for the fetus to pass through.
2 Delivery of Baby Stage two involves the actual
birth, or delivery, of the baby. This stage can take from
half an hour to more than two hours. Contractions of the
uterus continue, and the baby is pushed out, usually head
first, through the cervix and vagina.
Once the baby is out, the doctor clamps and cuts the
umbilical cord. There are no nerve endings in the cord, so
this does not hurt the baby or the mother. The baby’s nose
and mouth are suctioned to remove mucus and make
breathing easier. Eye drops are put in the baby’s eyes to
prevent infection, and an injection of vitamin K is given
to prevent excessive bleeding from the cut umbilical cord.
The doctor may also prick the baby’s heel for a blood
sample, which will be tested for abnormal protein levels.
Abnormal test results may indicate a genetic disorder.
3 Delivery of Afterbirth Even though the baby
is born, the birth process is not complete. The third stage
involves contractions of the uterus that push out the
placenta, also called the afterbirth. This stage typically
takes about 15 to 30 minutes.
L2 Adapted Reading/Note Taking 19-3
The Birth Process
L2 Visual Learning: Figure 6
Placenta
1 Labor
2 Delivery of Baby
Partially separated
placenta
3 Delivery of Afterbirth
Pregnancy, Birth, and Childhood 499
Have students make a flowchart that
details the three stages in the birth
process. Students should include the
time frame for each stage as well as a
brief description of what occurs, including the names of structures involved in
the process.
Teaching Transparency 56
Use the illustrations in Figure 6 to
discuss the three stages of the birth
process. Ask: What happens during
labor? (Contractions of muscles in the
uterus cause the cervix to increase in
width.) What happens during the
second stage of birth? (the delivery of
the baby) Point out how the cervix has
opened up, allowing the baby to be
pushed out of the body. Then ask: Why
does the birth process not end after the
birth of the baby? (The uterus pushes
out the placenta, or afterbirth, in the
third stage of the birth process.)
L4 Building Health Skills
Umbilical cord
L2 Less Proficient Readers
L3 EL Reading/Note Taking 19-3
Accessing Information Have students
find out the types of birthing facilities
available in their community. (Some
communities have both hospitals and
birthing centers for women to choose
from.) Students should find out how
these facilities address the medical and
comfort needs of both the parents and
their newborns during the birth
process. Students should learn how long
mothers and their newborns stay in the
facility after birth, as well as whether
the infant and father can stay in the
mother’s room. Students can create a
brochure or poster summarizing what
they learned.
L3 Addressing Misconceptions
Childbirth Pain Some students may not
realize that childbirth is painful. Explain
that pain is caused by the strong contractions of the uterine muscles, as well as
the pressure from the baby pushing on
the cervix. Show students brochures
describing childbirth classes given by
local hospitals, birthing centers, or
medical clinics. Point out how many
give instruction on relaxation techniques to help women deal with the
pain. Medications developed specifically
for women in labor may also be used.
Pregnancy, Birth, and Childhood
499
Chapter 19, Section 3
Hands-On Activity
Be a Parent for a Day
Suggest that students keep a written
log or diary in which they record their
thoughts and feelings as they take care
of their “baby.” Also have students
record any lapses they had, how they
chose a book to read to the “baby,”
and who took care of the “baby” if
they had to go out.
Be a Parent for a Day
Materials
Try This
5-pound bag of flour
plastic bag with tie
1 Place the bag of flour inside the plastic bag and
Think and Discuss
1. Sample answers: My free time was
limited; I found myself worrying
about the baby; I resented not being
able to do what I wanted.
2. It is about the same size and weight
as a baby.
Think and Discuss
1 How did being a parent of a bag of flour affect your lifestyle?
3. The best time is when a couple is
emotionally and financially ready
to have a baby and has planned for
the baby.
2 In what ways is a bag of flour an appropriate object to use to
represent a baby?
3 When do you think is the best time for a person to become a
parent? Explain.
L2 Class Discussion
The Postpartum Period After the birth, a period of adjustment
for the parents and their newborn begins. During the first six weeks, called
the postpartum period, many changes take place. Immediately after the
birth, the newborn’s lungs begin to function for the first time. The circulatory system and heart undergo changes that send more blood to the
lungs, where the baby now gets oxygen from the air. The nervous system
reacts to new sensations: light, air against the skin, a parent’s touch,
hunger, and pain. While its organs adjust to life outside the uterus, the
newborn is learning to get what it needs by forming a strong bond with
its mother and father.
For the mother, changing hormone levels signal the breasts to produce milk and cause the uterus to gradually shrink back to its normal size.
Hormonal changes and fatigue may cause the mother to feel overwhelmed,
or even very sad, during the postpartum period. Usually, these “baby
blues” pass within a few days. If, however, the sadness lasts longer or causes
the mother to withdraw from the baby and other people, she should seek
prompt medical attention. She may need to be treated for a serious condition called postpartum depression.
Make a chart on the board to summarize the changes that a newborn and
mother undergo during the postpartum
period. Ask: What changes occur in the
newborn? (Lungs begin to function,
circulatory system and heart change,
nervous system reacts to new stimuli,
infant bonds with parents.) Point out
that these changes are due to the
newborn’s change in environment.
What changes does the mother go
through? (Breasts produce milk, uterus
shrinks in size, hormonal changes,
fatigue, may become depressed.) Explain
that the mother’s body is healing from
the pregnancy and birth, as well as
preparing to nourish the baby.
L3 Cultural Connection
During the pregnancy or postpartum
period, parents choose a name for their
newborn. Names often have cultural or
family significance. Ask students to find
out how and why their names were
chosen. Have volunteers share their
findings with the class.
500
Chapter 19
fasten it shut. For the next 24 hours, you will be
responsible for your bag of flour as if it were a
real baby.
2 Choose a name for your “baby.”
3 Follow these rules for taking care of your “baby.”
• Every 5 hours, including night, feed your “baby”
for 20 minutes. During this time, you must remain
seated in one place and devote your full attention
to your “baby.”
• Every 3 hours during the time that you are awake, allow
5 minutes for changing your “baby’s” diaper.
• Spend 15 minutes in the evening talking or reading
to your “baby.”
• Never leave your “baby” alone. If necessary, arrange
for someone to babysit.
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Chapter 19
I!
FY
Benefits of Breast Milk
In most cases, breast milk is the ideal food for
newborns. It contains antibodies to disease,
and it is nonallergenic. The act of breastfeeding is beneficial because it requires close
physical contact, which benefits both mother
and child.
Prolactin is present throughout pregnancy.
With estrogen, it prepares the breasts to
produce milk. Little milk is produced until
after the baby is born, however. The
reason is that before birth, estrogen and
progesterone released by the placenta
inhibit the actions of prolactin. Estrogen
and progesterone levels fall drastically
following delivery of the placenta, so the
effects of prolactin are no longer inhibited
and milk is formed.
Complications at Birth
Complications at Birth
Although the birth process usually proceeds smoothly, problems can
sometimes occur. Some complications result in a surgical delivery or
premature birth. Low birthweight and the birth of more than one baby
also may cause complications. In addition, very rarely, a pregnancy may
end with a stillbirth. A stillbirth occurs when a fetus dies and is expelled
from the body after the twentieth week of pregnancy.
L3 Online Activity
PHSchool.com
Use the Web Code to
access an online activity about the birth
process. Have students complete the
Web activity.
For: More on the birth
process
Visit: PHSchool.com
Web Code: ctd-6193
L3 Cooperative Learning
Surgical Delivery Sometimes delivery through the cervix and
vagina is not possible because of the position of the fetus in the uterus or
the narrowness of the mother’s hips. Other times, illness or other conditions may make labor and vaginal delivery dangerous for the mother or
the fetus.
In these circumstances, the obstetrician will perform a cesarean section. A cesarean section (suh ZEHR ee un) is a surgical method of birth.
The operation takes about one hour to complete, and the mother may be
awake or asleep during the procedure. First the doctor makes an incision
in the lower abdomen into the uterus. Then he or she removes the baby
and placenta. About 30 percent of all babies born in the United States are
delivered by cesarean section.
Divide the class into groups of four or
five, and assign each group one of the
following birth complications: stillbirth,
premature birth, and low birthweight.
For each complication, ask students to
learn more about what it is and its
possible causes, if known. Then
challenge students to think of ways
in which the complication might be
prevented. Instruct students to make a
poster that displays this information
about the complication and present it
to the class.
Premature Birth Sometimes a baby is born before it has developed
fully. Delivery of a live baby before the 37th week of pregnancy is called
premature birth. The earlier the birth, the more problems the baby tends
to have. The lungs of a premature baby are usually not fully developed,
and in some cases, the baby cannot breathe by itself. The baby may also
have additional problems if other organs aren’t fully developed. A premature baby may receive care in an incubator, a chamber designed to protect
the baby until it has developed more.
Connect to
YOUR LIFE
What misconceptions about premature babies did
you hold before reading this section?
L2 Building Vocabulary
FIGURE 7 A premature baby may
need extended hospital care until it
becomes more fully developed.
On average, hospital costs
for premature babies
are 14 times as high
as costs for
healthy newborns.
501
L2 Visual Learning: Figure 7
Invite students to compare the size of
the baby in the photograph with the
size of the adult’s hand. Then ask: Why
do you think the hospital costs for premature babies are so much higher than
the costs for healthy newborns?
(Sample answer: Premature babies are
in the hospital for a longer period of
time and require more specialized care.)
Explain that in some cases, premature
babies continue growing and developing in incubators where they receive
only intravenous feedings until their
digestive system is able to digest
breast milk.
Connect to Sample answer: that premaYOUR LIFE ture babies were fully devel-
L4 Gifted and Talented
Have students research other complications
that occur at birth and how these complications are handled. (Complications that
students might choose include fetal aspiration of meconium during birth, unproductive labor, breech fetus, or an umbilical
Explain that the term cesarean section is
derived from the Latin phrase a caeso
matris utere, which means “from the
cut womb of his mother.” Then have
students write a paragraph relating the
Latin phrase to the current meaning
and summarizing the information they
learned about the procedure from the
text.
cord that is expelled before the fetus is
delivered.) Students should prepare a
presentation to the class on their findings
using a poster, presentation software, or
other visuals.
oped, only smaller
Pregnancy, Birth, and Childhood
501
Chapter 19, Section 3
FIGURE 8 Risk factors for
having a baby with low
birthweight include smoking or
dieting during pregnancy and
teenage pregnancy.
L3 Building Health Skills
Advocacy Have student groups prepare
a brochure advocating ways to prevent
low birthweight babies. Students should
include preventive measures pregnant
women can take such as not smoking,
eating well, exercising, and making
regular prenatal doctor visits. Teenage
pregnancy also carries the risk of low
birthweight. Encourage students to
produce brochures that are suitable
for distribution in public places, such
as libraries, schools, and doctor’s
offices.
Babies born to
teen mothers are at
increased risk for
low birthweight.
Low Birthweight A newborn that weighs less than 5.5 pounds at
birth is considered to have low birthweight. Some low-birthweight
babies are also premature. Others are full-term, but they just didn’t
grow enough before birth.
Premature and low-birthweight babies face an increased risk of health
problems as newborns, chronic lifelong health problems, and even death.
Not all cases are preventable. However, the number of premature and lowbirthweight babies could dramatically decrease if more women adopted
healthy habits during pregnancy. For example, a woman reduces her risk
of having a baby with low birthweight by about 40 percent by not smoking during pregnancy.
Multiple Births
L2 Visual Learning: Figure 9
Teaching Transparency 57
Use Figure 9 to compare the formation
of fraternal and identical twins. Point
out that fraternal twins develop when
an ovary releases two eggs. This event
can be due to an inherited tendency or
to hormone therapy, which is used to
improve fertility. Ask: Can fraternal
twins be the same sex? Explain. (Yes,
the two sperm cells fertilizing the eggs
carry the same type of sex chromosome.) Can identical twins be different
sexes? Explain. (No, identical twins
form when one embryo splits, so both
embryos are identical.)
Caption Answer Two different sperm
fertilize two different eggs with fraternal twins, so each fertilized egg has a
different genetic makeup. Identical
twins develop from identical embryos.
Multiple Births
The delivery of more than one baby—for example, twins, triplets, or
quadruplets—is called a multiple birth. These births carry greater risk to
the mother and babies, and are closely monitored by doctors. Delivery by
cesarean section is more likely for a multiple birth than for a single birth.
What causes more than one fetus to develop? Figure 9 shows how the
two types of twins develop.
Identical Twins Twins that develop from a single fertilized egg, or
zygote, are called identical twins. Early in development, the embryo divides
into two identical embryos. Because they develop from identical embryos,
identical twins have the same inherited traits and are the same sex.
Fraternal Twins Sometimes two eggs are released from the ovary
and are fertilized by two sperm. When this happens, fraternal twins
develop. Fraternal twins are no more alike than any other siblings, and
they may or may not be the same sex.
L4 Active Learning
Invite students to research current findings about the personality traits of
identical twins, especially those that
were separated at birth. Encourage
students to present their findings to
the class.
Triplets or More Triplets, quadruplets, and other multiple births
are less common than twins. But the number of births with three or more
babies has increased dramatically in the last 25 years.
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Chapter 19
and Health
L3 Percentages
Divide the class into groups and assign
each group a grade (9th, 10th, and so on).
Ask each group to determine how many
twins are in its assigned grade. Ask
students to report both the number of
twins and the percentage of twins. Then
pool the data and calculate the percent-
502
Chapter 19
age of twins in the school population.
Have students compare their percentage
with the national percentage, which was
3.15 percent in 2003. If students differentiated between identical and fraternal
twins, ask them to calculate a percentage
for each category.
Identical Twins
Fraternal Twins
A sperm fertilizes a single egg.
Two different sperm fertilize two eggs.
3. Assess
Evaluate
These assignments can help you assess
students’ mastery of the section content.
Section 3 Review
Answers appear below.
Early in development, the embryo splits
and forms two identical embryos.
Each of the fertilized eggs
develops into an embryo.
Teaching Resources
• Practice 19-3
• Section 19-3 Quiz
L2 Reteach
Fraternal twins result.
Identical twins result.
Have student pairs work together to
construct a concept map for the section.
Students should include the stages
in the birth process, complications in
childbirth, and the different kinds of
multiple births. Challenge students to
include all the vocabulary terms from
the section.
L4 Enrich
Teaching Resources
• Enrich 19-3
Health at
Identical twins inherit identical traits, whereas
fraternal twins do not. Applying Concepts Why can
fraternal twins be different sexes while identical twins cannot?
FIGURE 9
Health at School
Section 3 Review
Twins Interview Interview twins you know at
your school or in your community. Ask them
how they think being twins affects their
relationship as siblings. Write a transcript of
your interview.
Key Ideas and Vocabulary
1. What are the three stages of birth?
2. Describe what happens during labor.
3. What is the postpartum period? List two changes
that happen in the newborn and two changes that
happen in the mother during this period.
4. What are four complicating factors that may arise
at birth?
5. What is a cesarean section? Give two reasons why
a cesarean section may be performed.
School
Twins Interview Have students prepare a list of questions before interviewing the twins. For the transcript,
students should write their questions
followed by the twins’ responses. If
students wish, they may record the
interview (with the twins’ permission)
and play it back later to transcribe it.
Critical Thinking
6. Relating Cause and Effect Describe two risk
factors for low birthweight.
7. Comparing and Contrasting How do fraternal
twins differ from identical twins?
Pregnancy, Birth, and Childhood 503
5. a surgical method of birth in which
the doctor makes an incision in the
lower abdomen and removes the
baby and placenta; position of fetus
or hips too narrow
Section 3 Review
1. labor, delivery of the baby, delivery of the
afterbirth
2. Strong contractions of the muscles of the
uterus cause the cervix to dilate. Then the
amniotic sac breaks, and the cervix becomes
softer and wide enough for the fetus to
pass through.
4. cesarean section, premature birth,
low birthweight, multiple births
3. the first six weeks after birth; any two newborn changes: lungs function, circulatory
system sends blood to lungs, nervous system reacts to new sensations, forms bond
with parents; any two mother changes:
breasts produce milk, uterus shrinks, hormonal changes, fatigue
6. any two: smoking or dieting during
pregnancy, teenage pregnancy
7. Fraternal twins develop from two
different eggs that are fertilized by
two different sperm. Identical twins
develop from a single embryo that
divides into two embryos.
Pregnancy, Birth, and Childhood
503