Chapter 12: Conception and Prenatal Development McKinney: Evolve Resources for Maternal-Child Nursing, 5th Edition

Which part of the mature sperm contains the male chromosomes?

a. The head of the sperm

b. The middle portion of the sperm

c. X-bearing sperm

d. The tail of the sperm

ANS: A The head of the sperm

The head of the sperm contains the male chromosomes that will join the chromosomes of

the ovum. The middle portion of the sperm supplies energy for the tail's whip-like action. If

an X-bearing sperm fertilizes the ovum, the baby will be female. The tail of the sperm helps

propel the sperm toward the ovum.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: p. 197 OBJ: Integrated Process: Teaching-Learning

MSC: Client Needs: Physiologic Integrity

One of the assessments performed in the delivery room is checking the umbilical cord

for blood vessels. Which finding is considered within normal limits?

A. Two arteries and one vein

B. Two arteries and two veins

C. Two veins and one artery

D. One artery and one vein

ANS: A Two arteries and one vein

The umbilical cord contains two arteries and one vein to transport blood between the fetus

and the placenta. Any option other than two arteries and one vein is considered abnormal and

requires further assessment.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: p. 206 OBJ: Nursing Process: Asses

The purpose of the ovum's zona pellucida is to

A. make a pathway for more than one sperm to reach the ovum.

B. allow the 46 chromosomes from each gamete to merge.

C. prevent multiple sperm from fertilizing the ovum.

D. stimulate the ovum to begin mitotic cell division.

ANS: C prevent multiple sperm from fertilizing the ovum.

Fertilization causes the zona pellucida to change its chemical composition so that multiple

sperm cannot fertilize the ovum. Each gamete (sperm and ovum) has only 23 chromosomes.

There will be 46 chromosomes when they merge. Mitotic cell division begins when the

nuclei of the sperm and ovum unite.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: p. 195 OBJ: Integrated Process: Teaching-Learning

While teaching an early pregnancy class, the nurse explains that the morula is a

A. fertilized ovum before mitosis begins.

B. flattened disk-shaped layer of cells within a fluid-filled sphere.

C. double layer of cells that becomes the placenta.

D. solid ball composed of the first cells formed after fertilization.

ANS: D solid ball composed of the first cells formed after fertilization.

The morula is so named because it resembles a mulberry. It is a solid ball of 12 to 16 cells that

develops after fertilization. The fertilized ovum is called the zygote. This is the embryonic

disk. It will develop into the baby. The placenta is formed from two layers of cells: the

trophoblast, which is the other portion of the fertilized ovum, and the decidua, which is the

portion of the uterus where implantation occurs.

PTS: 1 DIF: Cognitive Level: Comprehension/Understanding

The nursing faculty explains to students that the upper uterus is the best place for the

fertilized ovum to implant because it is here that the

a. placenta attaches most firmly.

b. developing baby is best nourished.

c. uterine endometrium is softer.

D. maternal blood flow is lower.

ANS: B developing baby is best nourished.

The uterine fundus is richly supplied with blood and has the thickest endometrium, both of

which promote optimal nourishment of the fetus. If the placenta attaches too deeply, it does

not easily detach after birth. Softness is not a concern with implantation; attachment and

nourishment are the major concerns. The blood supply is rich in the fundus, which allows

for optimal nourishment of the fetus.

PTS: 1 DIF: Cognitive Level: Comprehension/Understanding

The student nurse learns that some of the embryo's intestines remain within the umbilical cord

during the embryonic period because the

a. umbilical cord is much larger at this time than it will be at the end of pregnancy.

b. intestines begin their development within the umbilical cord.

c. nutrient content of the blood is higher in this location.

d. abdomen is too small to contain all the organs while they are devel

ANS: D abdomen is too small to contain all the organs while they are developed

The abdominal contents grow more rapidly than the abdominal cavity, so part of their

development takes place in the umbilical cord. By 10 weeks, the abdomen is large enough to

contain them. The intestines remain within the umbilical cord only until approximately week

10.Intestines begin their development within the umbilical cord but only because the liver

and kidneys occupy most of the abdominal cavity. All the intestines are within the abdominal

cavity around week 10.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

A woman is 16 weeks pregnant with her first baby. She asks how long it will be before she

feels the baby move. The best answer is

A. "You should have felt the baby move by now."

B. "Within the next month, you should start to feel fluttering sensations."

C. "The baby is moving, but you can't feel it yet."

D. "Some babies are quiet, and you don't feel them move."

ANS: B "Within the next month, you should start to feel fluttering sensations."

Maternal perception of fetal movement usually begins 17 to 20 weeks after conception,

particularly if this is the first pregnancy. "The baby is moving, but you can't feel it yet" is a

true statement. The fetus's movements are not strong enough to be felt until 17 to 20 weeks;

however, this statement does not answer the concern of the woman. If no movement is felt at

the end of 20 weeks, further assessment is needed.

PTS: 1 DIF: Cognitive Level: Comprehension/Understanding

REF: p. 204 OBJ: Nursing Process: Implementat

During a pregnancy group meeting, the nurse teaches patients that the fetal period is

best described as one of

a. development of basic organ systems.

b. resistance of organs to damage from external agents.

c. maturation of organ systems.

d. development of placental oxygen-carbon dioxide excha

ANS: C maturation of organ systems.

During the fetal period, the body systems grow in size and mature in function to allow

independent existence after birth. Basic organ systems are developed during the embryonic

period. The organs are always at risk for damage from external sources; however, the older

the fetus, the more resistant the organs will be. The greatest risk is when the organs are

developing. The placental system is complete by week 12, but that is not the best

description of the fetal period.

PTS: 1 DIF: Cognitive Level: Comprehension/Understanding

REF: p. 204 OBJ: Integrated Process: Teaching-Learnin

A new mother is distresses over the "white substance" covering her infant because it

"looks ugly." What action by the nurse is most appropriate?

A. Scrub the substance off of the baby.

B. Reassure the mom that it will go away.

C. Report the findings to the provider.

D. Explain that the vernix caseosa protects fetal skin from amniotic flui

ANS D Explain that the vernix caseosa protects fetal skin from amniotic fluids

Prolonged exposure to amniotic fluid during the fetal period could result in breakdown of

the skin without the protection of the vernix caseosa. This can be washed off gently, when

the baby gets the first bath. Although it will not remain, this statement does not explain the

purpose of the substance. This does not need to be reported.

PTS: 1 DIF: Cognitive Level: Comprehension/Understanding

REF: p. 204 OBJ: Integrated Process: Teaching-Learning

A woman who is 16 weeks pregnant asks the nurse, "Is it possible to tell by ultrasound if the

baby is a boy or girl yet?" The best answer is

a. "A baby's sex is determined as soon as conception occurs, and the differences are

apparent."

b. "The baby has developed enough that we can determine the sex by examining

the genitals through ultrasound."

c. "Boys and girls look alike until approximately 20 weeks after conception, and

then they begin to look different."

d. "It might be possible to determine your baby's sex, but the external organs look

very similar right now."

ANS: B "The baby has developed enough that we can determine the sex by examining

the genitals through ultrasound."

Although gender is determined at conception, the external genitalia of males and females

look similar through the 9th week. By the 12th week, the external genitalia are

distinguishable as male or female.

PTS: 1 DIF: Cognitive Level: Comprehension/Understanding

REF: p. 204 OBJ: Integrated Process: Teaching-Learning

The placenta allows exchange of oxygen, nutrients, and waste products between the

mother and fetus by

a. contact between maternal blood and fetal capillaries within the chorionic villi.

b. interaction of maternal and fetal pH levels within the endometrial vessels.

c. a mixture of maternal and fetal blood within the intervillous spaces.

d. passive diffusion of maternal carbon dioxide and oxygen into the fetal capillaries.

ANS: A contact between maternal blood and fetal capillaries within the chorionic villi.

Fetal capillaries within the chorionic villi are bathed with oxygen- and nutrient-rich maternal

blood within the intervillous spaces. The endometrial vessels are part of the uterus. There is

no interaction with the fetal blood at this point. Maternal and fetal blood do not normally

mix. Maternal carbon dioxide does not enter into the fetal circulation.

PTS: 1 DIF: Cognitive Level: Knowledge/Understanding

REF: p. 206 OBJ: Integrated Process: Teaching-Learning

A patient is sent from the physician's office for assessment of oligohydramnios. The nurse is aware that this condition can result in

a. excessive fetal urine secretion.

b. newborn respiratory distress.

c. central nervous system abnormality.

d. gastrointestinal blockage.

ANS: B newborn respiratory distress.

Because an abnormally small amount of amniotic fluid restricts normal lung development, the

infant may have inadequate respiratory function after birth, when the placenta no longer

performs respiratory function. Oligohydramnios may be caused by a decrease in urine

secretion. Excessive amniotic fluid production may occur when the fetus has a central

nervous system abnormality. Excessive amniotic fluid production may occur when the

gastrointestinal tract prevents normal ingestion of amniotic fluid.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

When explaining twin conception, the nurse points out that dizygotic twins develop from

A. a single fertilized ovum and are always of the same sex.

B. a single fertilized ovum and may be the same sex or different sexes.

C. two fertilized ova and are the same sex.

D. two fertilized ova and may be the same sex or different sexes.

ANS: D two fertilized ova and may be the same sex or different sexes.

Dizygotic twins are two different zygotes, each conceived from a single ovum and a single

sperm. They may be both male, both female, or one male and one female. A single fertilized

ovum that produces twins is called monozygotic. Monozygotic twins are always the same

sex. Dizygotic twins are from two fertilized ova and may or may not be the same sex.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: p. 213 OBJ: Integrated Process: Teaching-Learning

MSC:

Which statement related to oogenesis is correct?

A. Two million primary oocytes will mature.

B. At birth, all ova are contained in the female's ovaries.

C. The oocytes complete their division during fetal life.

D. Monthly, at least two oocytes mature.

ANS: B At birth, all ova are contained in the female's ovaries.

All of the cells that may undergo meiosis in a woman's lifetime are contained in the ovaries at

birth. Only 400 to 500 ova will mature during the approximately 35 years of a woman's

reproductive life. The primary oocytes begin their first meiotic division during fetal life but

remain suspended until puberty. Every month, one primary oocyte matures and completes

meiotic division yielding two unequal cells.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: p. 195 OBJ: Integrated Process: Teaching-Lear

After implantation, tiny projections develop out of the trophoblast and extend into

the endometrium. These projections are referred to as

a. decidua basalis.

b. decidua capsularis.

c. decidua vera.

d. chorionic villi.

ANS: D chorionic villi.

These villi are vascular processes that obtain oxygen and nutrients from the maternal

bloodstream and dispose of carbon dioxide and waste products into the maternal blood. The

deciduas basalis is the portion of the endometrium where the chorionic villi tap into the

maternal blood vessels. The deciduas capsularis is the portion of the endometrium that covers

the blastocyst. The portion of the endometrium that lines the rest of the uterus is called

decidua vera.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: p. 199 OBJ: Integrated Process: Teaching-Learning

A nurse is teaching a prenatal class. The nurse teaches that during weeks 25 to 28, which fetal

development occurs?

a. Eyes reopen.

b. Vernix caseosa covers the skin.

c. Lanugo may develop.

d. Brown fat is deposited.

ANS: A Eyes reopen.

During this time frame the eyes reopen, and the fetus becomes plumper with smoother skin.

The other changes occur during weeks 17 to 20.

PTS: 1 DIF: Cognitive Level: Comprehension/Understanding

REF: p. 206 OBJ: Integrated Process: Teaching-Learning

MSC: Client Needs: Physiologic Integrity

A young patient comes in for her first prenatal examination. This is her first child. She asks

"How does my baby get air inside my uterus?" The correct response is

a. "The baby's lungs work in the uterus to exchange oxygen and carbon dioxide."

B. "The baby absorbs oxygen from your blood system."

C. "The placenta provides oxygen to the baby and excretes carbon dioxide into your bloodstream."

d. "The placenta delivers oxygen-rich blood through the umbilical artery to the baby's abdomen."

ANS: C "The placenta provides oxygen to the baby and excretes carbon dioxide into your bloodstream."

The placenta functions by supplying oxygen and excreting carbon dioxide to the maternal

bloodstream. The fetal lungs do not function for respiratory gas exchange in utero. The baby

does not simply absorb oxygen from a woman's blood system. Blood and gas transport occurs

through the placenta. The placenta delivers oxygen-rich blood through the umbilical vein, not

artery.

PTS: 1 DIF: Cognitive Level: Comprehension/Understanding

REF: p. 206 OBJ: Integrated Process: Teaching-L

The most basic information a maternity nurse should have concerning conception is

A. ova are considered fertile 48 to 72 hours after ovulation.

B. sperm remain viable in the woman's reproductive system for an average of 12 to 24 hours.

C. conception is achieved when a sperm successfully penetrates the

membrane surrounding the ovum.

D. implantation in the endometrium occurs 6 to 10 days after conception.

ANS: D implantation in the endometrium occurs 6 to 10 days after conception.

Implantation occurs 6 to 10 days after conception and is complete after 10 days. Ova are

considered fertile for approximately 24 hours after ovulation. Sperm remain viable in the

woman's reproductive system for an average of 2 to 3 days. Penetration of the ovum by the

sperm is called fertilization. Conception occurs when the zygote, the first cell of the new

individual, is formed.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: p. 198 OBJ: Integrated Process: Teaching-Learning

MSC: Client Needs: Physiologic Integrity

With regard to the structure and function of the placenta, the maternity nurse should be aware

that

a. as the placenta widens, it gradually thins to allow easier passage of air

and nutrients.

b. c. as one of its early functions, the placenta acts as an endocrine gland.

the placenta is able to keep out most potentially toxic substances, such as

cigarette smoke, to which the mother is exposed.

d. optimal blood circulation is achieved through the placenta when the woman

is lying on her back or standing.

ANS: B c. as one of its early functions, the placenta acts as an endocrine gland.

the placenta is able to keep out most potentially toxic substances, such as

cigarette smoke, to which the mother is exposed.

The placenta produces four hormones necessary to maintain the pregnancy. The placenta

widens until week 20 and continues to grow thicker. Toxic substances such as nicotine and

carbon monoxide readily cross the placenta into the fetus. Optimal circulation occurs

when the woman is lying on her side.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: p. 206 OBJ: Integrated Process: Teaching-Learning

MSC: Client Needs: Physiologic Integrity

Which statement is accurate about the development of fetal organs and systems?

a. The cardiovascular system is the first organ system to function in the developing human.

B. Hematopoiesis originating in the yolk sac begins in the liver at 10 weeks.

C. The body changes from straight to C-shaped at 8 weeks.

D. The gastrointestinal system is mature at 32 weeks.

ANS: A The cardiovascular system is the first organ system to function in the developing human.

The heart is developmentally complete by the end of the embryonic stage.

Hematopoiesis begins in the liver during the 6th week. The body becomes C-shaped at

21 weeks. The gastrointestinal system is complete at 36 weeks.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: p. 204 OBJ: Integrated Process: Teaching

What does the student learn about recent trends in multiple births?

A. The rate of twin births has declined.

B. The rate of higher order pregnancies has increased.

C. Higher order pregnancies are now very rare.

D. Twinning is the most common form of multiple pregnan

ANS: D Twinning is the most common form of multiple pregnancy

Twinning is the most common form of multiple pregnancy, and the rate has been increasing,

not declining. Higher order births increased for a time but have now decreased, although

they are not rare.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: p. 212 OBJ: Integrated Process: Teaching-Learning

MSC: Client Needs: Health Promotion and Maintenance

The nurse assesses pregnant women for exposure to human teratogens, including which of

the following? (Select all that apply.)

a. Infections

b. Radiation

c. Maternal conditions

d. Drugs

e. Chemicals

ANS: A, B, C, D

Exposure to radiation and a number of infections may result in profound congenital

deformities. These include varicella, rubella, syphilis, parvovirus, CMV, and toxoplasmosis.

Certain maternal conditions such as diabetes and PKU may also affect organs and other parts

of the embryo during this developmental period. Drugs such as antiseizure medication and

some antibiotics, as well as chemicals including lead, mercury, tobacco, and alcohol, also may

result in structural and functional abnormalities. Coffee is not considered a teratogen.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: Appendix A OBJ: Nursing Process: Assessment

MSC: Client Needs: Physiologic Integrity

The nursing faculty teaches that the placenta produces many hormones necessary for

normal pregnancy. These include (Select all that apply.)

a. human chorionic gonadotropin (hCG).

b. insulin.

c. estrogen.

d. progesterone.

e. testosterone.

ANS: A, C, D

The placenta produces hCG, estrogen, and progesterone. It does not produce insulin or testosterone

PTS: 1 DIF: Cognitive Level: Comprehension/Understandi

The student learns about shunts that support fetal circulation. Which of the following

are included in this support system? (Select all that apply.)

a. Ductus venosus

b. Foramen ovale

c. Ductus arteriosus

d. Foramen magnum

e. Ductus deferens

ANS: A, B, C

The ductus venosus, foramen ovale, and ductus arteriosus are part of fetal circulation. The

foramen magnum is located at the base of the skull. The ductus (or vas) deferens is part of the

male reproductive system.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: p. 210 OBJ: Integrated Process: Teaching-Learning

MSC: Client Needs: Physiologic Integrity

The nursing faculty explains that the fetus can survive in a low-oxygen environment due

to which of the following? (Select all that apply.)

A. Fetal hemoglobin carries more oxygen than an adult's.

B. The fetus has higher average hemoglobin and hematocrit.

C. Hemoglobin carries more oxygen at low partial pressures of carbon dioxide.

D. Fetal blood is more acidic than the maternal blood.

E. The fetus does not need gas exchange while in utero.

ANS: A, B, C

The fetus can survive in low oxygen environments due to its hemoglobin being able to carry

more oxygen that the mom, having a higher level of hemoglobin and hematocrit, and the fact

that hemoglobin can carry more oxygen at low partial pressures of carbon dioxide. Fetal

blood is alkaline. The fetus does need gas exchange in utero.

PTS: 1 DIF: Cognitive Level: Knowledge/Remembering

REF: p. 208 OBJ: Integrated Process: Teaching-Learning

MSC: Client Needs: Physiologic Integ