Chapter 5: Fetal Development

A pregnant patient is concerned that the baby is going to drown in the uterus because of the fluid. What should the nurse respond about fetal respiration?

"Oxygen is provided to the baby through the placenta." Fetal circulation differs from extrauterine circulation because the fetus derives oxygen and excretes carbon dioxide not from gas exchange in the lung but from exchange in the placenta. The baby's lungs are not functioning in utero so the response that the baby's breathing is very minor until delivery and the baby's lungs being able to accommodate the fluid are incorrect. The patient is not "breathing for the baby."

During a prenatal visit, a pregnant woman says, "I know the amniotic fluid is important, but can you tell me more about it?" When describing amniotic fluid to a pregnant woman, which description would the nurse most likely include?

"This fluid acts as a cushion to help to protect your baby from injury." Amniotic fluid protects the floating embryo and cushions the fetus from trauma. The placenta acts as a transport mechanism for oxygen and nutrients. Amniotic fluid is primarily water with some organic matter. Throughout pregnancy, amniotic fluid volume fluctuates.

After completing an assessment, the nurse suspects a woman has confused implantation bleeding with her period. The nurse predicts the woman is at which week in her pregnancy?

4 weeks It is important to ask about the date of the last normal period. If a woman confuses implantation bleeding with her period, the pregnancy is 4 weeks older than she thinks.

A nurse is describing the development of the fetus to a group of pregnant women. When describing the function of the placenta, which information would the nurse most likely include? Select all that apply.

It supplies oxygen and nutrients to the fetus. It produces hormones that help maintain the pregnancy. It carries waste away for excretion by the mother. The placenta supplies the developing organism with food and oxygen, carries waste away for excretion by the mother, slows the maternal immune response so that the mother's body does not reject the fetal tissues, and produces hormones that help maintain the pregnancy. Wharton's jelly protects the umbilical cord and the foramen ovale permits most of the blood to bypass the right ventricle. The amniotic fluid cushions the fetus against injury.

During a preconception teaching session, the nurse tells participants to increase their intake of which food groups to reduce the incidence of neural tube disorders? Select all that apply.

Leafy green vegetables Sunflower seeds Orange fruits Entering pregnancy with an optimum folic acid level decreases the incidence of neural tube closure failures. Leafy green vegetables, sunflower seeds and orange fruits are naturally high in folic acid. Lean meats and milk provide protein.

An infant was born at term but has intrauterine growth restriction (IUGR). What findings in the infant's history would contribute to this problem? Select all that apply.

Maternal smoking Intrauterine infection of the fetus There are a number of contributory causes for IUGR in a fetus, including maternal smoking or drug/alcohol use, infections such as cytomegalovirus and rubella, maternal hypertension, and chronic maternal diseases such as sickle cell disease or renal disease. Maternal heartburn is a normal maternal complaint and does not affect the fetal well being Small parents could cause a fetus to be small, but would not cause IUGR. Maternal exercise does not cause IUGR.

An expectant mother asks the nurse which of her antibodies from previous immunizations would be passed to her fetus during pregnancy. Which response by the nurse would be correct?

Measles antibodies will cross the placenta to protect the fetus. Some maternal antibodies passively cross the placenta in pregnancy. These include measles, diphtheria and smallpox. Those not crossing are rubella, cytomegalovirus, and varicella. Annual flu shots do not cross the placenta either.

When a man ejaculates, his sperm begin a long and arduous journey to fertilize the woman's ovum. What in the semen produces smooth muscle contractions in the uterus to help the sperm along on their journey?

Prostaglandins Prostaglandins in the semen increase smooth muscle contractions of the uterus that facilitate the transport of sperm.

The nurse is explaining the ultrasound procedure to a pregnant client and mentions part of the purpose is to evaluate the amniotic fluid. When questioned by the client how the amniotic fluid helps the fetus, which functions should the nurse point out? Select all that apply.

Provides physical protection Helps regulate temperature Provides unrestricted movement Helps permit symmetrical growth Amniotic fluid fills the amniotic cavity. It serves four main functions for the fetus: physical protection, temperature regulation, provision of unrestricted movement, and symmetrical growth. The amniotic fluid does not produce hormones. Hormones are produced by the placenta.

A client at 20 weeks' gestation is admitted to the hospital birthing center with premature labor. What information regarding fetal lung development at this stage of development makes stopping the labor process beneficial?

Surfactant is not produced until the start of the 21st week of fetal development. The fetal lungs do not produce surfactant at 20 weeks. A preterm neonate without surfactant does not have the fat and protein coating that helps to decrease the surface tension in the alveoli. This lack of surfactant decreases the neonate's ability to exhale.

How does fetal circulation differ from circulation after birth?

The umbilical vein carries oxygenated blood, while deoxygenated blood is carried by the umbilical arteries. The umbilical vein carries oxygenated blood from the placenta to the fetus and the deoxygenated blood is returned to the placenta by the two umbilical arteries, whereby in circulation after delivery, oxygenated blood is carried by arteries and deoxygenated blood is carried by veins. The blood flow through the pulmonary artery is approximately 10% of the post-delivery blood flow due to high pulmonary vascular resistance in utero. The ductus arteriosus carries blood from the pulmonary artery to the aorta, not the blood coming from the left ventricle.

A client is confused concerning her fertile period each month. The nurse would educate the client by providing which information?

The window of opportunity for conception is from 3 days before to 2 days following ovulation. Since sperm are viable for 24 to 72 hours after ejaculation and the ovum remains fertile for a maximum of 48 hours after ovulation, the window is from 3 days before to 2 days after ovulation.

What should the nurse explain to the pregnant client about the importance of the fetal stage of development?

There is additional growth and development of the organs and body systems. The fetal stage is from the beginning of the ninth week after fertilization and continues until birth. At this time, the developing human is called a fetus. During the fetal stage, there is additional growth and maturation of the organs and body systems.

The fluid-filled, inner membrane sac surrounding the fetus is which structure?

amnion The fluid-filled, inner membrane sac surrounding the fetus is the amnion. The chorion is the outer membrane surrounding the fetus. The endometrium is the inner lining of the uterus. The decidua is the name used for the endometrium during pregnancy.

The nurse explains to a pregnant woman that the germ layers that develop in the embryo and become different organs and tissues consist of which layers? Select all that apply.

ectoderm mesoderm endoderm The three germ layers in the embryo are the ectoderm, mesoderm, and endoderm. The others are layers of the skin.

The nursing student is preparing a presentation that will illustrate the various stages of fetal development. The student will label which stage as the time when the various tissues of the growing embryo begin to assume specific functions?

embryonic During the embryonic period, the cells multiply and tissues begin to assume specific functions, a process known as differentiation. This stage lasts from the end of the second week after fertilization until the end of the eighth week. The pre-embryonic stage begins with fertilization and lasts for 2 weeks. Cellular division and implantation occur during this stage of development. The fetal stage is from the beginning of the ninth week after fertilization and continues until birth. There is additional growth and maturation of the organs and body systems during this time. There is no post-embryonic stage.

A nursing student is explaining to a newly pregnant woman what happens during each stage of fetal development. At which stage does the nurse inform the woman that the lungs are fully shaped?

end of 16 weeks At the end of 16 weeks, the lungs are fully shaped, fetus swallows amniotic fluid, skeletal structure is identifiable, downy lanugo hair is present on the body, and sex can be determined using ultrasound.

A client questions the nurse about how her fetus's gender is determined. The nurse's most accurate reply would be that gender of the fetus is determined when:

gametes from the mother and gametes from the father are joined during meiosis. Meiosis occurs in the testes and ovaries, which forms two gametes, containing a haploid number of chromosomes, which is 23, for each cell. The two gametes then join during fertilization to form the embryo. Mitosis is the division and replication of somatic or body cells, not chromosomes. Only chromosomes divide into haploid numbers, not somatic cells. Chromosomal division occurs in the testes and ovaries, not the uterus.

A woman has just learned that she is pregnant and would like to know how soon she can find out via ultrasound the sex of her fetus. The nurse should respond with which of the following?

At about 4 months Although fetal gender is usually determined by an ultrasound screen at about 4 months, it can be determined as early as 7 weeks by analysis of maternal serum.

What factors contribute to the increased probability of conceiving dizygotic twins? Select all that apply.

Being tall Being a twin herself The factors that contribute to having dizygotic twins are the mother being a twin herself, being tall or of large stature, getting pregnant shortly after stopping oral contraceptives, and being of black heritage. Advanced maternal age, having irregular menstrual cycles or conceiving while on oral contraceptives does not increase the chance of multifetal pregnancies.

A nurse is asked to auscultate the fetal heart sounds in a pregnant client. Which of the following equipment is most appropriate when auscultating fetal heart sounds at the 12th week?

Doppler Fetal heart sounds are best heard with the Doppler from the 10th week onward. They can be heard with the fetoscope by about the 18th to 20th week only. A tocodynometer is used to record uterine contractions and not to auscultate fetal heart tones. Fetal heart tones may not be audible with an ordinary stethoscope at the 12th week.

During the initial assessment of a preterm infant, it is noted that the infant has a heart murmur. Which shunt from fetal life most likely remains open?

Ductus arteriosus There are three shunts in the fetal circulation: the foramen ovale, the ductus venosus and the ductus arteriosus. Additionally, there are two umbilical arteries and one umbilical vein, which close following birth and form ligaments. In a preterm infant, there is a higher likelihood of the ductus arteriosus remaining open, so a murmur heard in a preterm infant shortly after birth would be suspected to be ductal murmur.

The nurse is teaching a class about conception. The nurse explains to the participant that which factors are necessary for conception to occur? Select all that apply.

Equal maturation of both sperm and ovum Ability of the sperm to reach the ovum Ability of the sperm to penetrate the ovum For conception to occur three factors must be present: equal maturation of the sperm and ovum, ability to the sperm to reach the ovum, and the ability of the sperm to penetrate the ovum. The ovum does not ingest the sperm; the ovum is passive and the sperm must penetrate the zona pellucida and cell membrane and achieve fertilization. The ovum is not motile. The ovum is propelled through the fallopian tube by the cilia lining the tube. Unlike the motile sperm, an ovum has no independent motility.

A pregnant client is diagnosed with hydramnios. The nurse explains that further testing will be done to determine if which conditions are present? Select all that apply.

Esophageal atresia Anencephaly Hydramnios or excessive amniotic fluid is found when the fetus has a condition such as esophageal atresia or anencephaly, which inhibit swallowing. Renal atresia or renal conditions that decrease urine production results in oligohydramnios. The volume of amniotic fluid protects the umbilical cord from pressure thus protecting the fetal oxygen supply.

After the nurse describes fetal circulation to a pregnant woman, the woman asks why her fetus has a different circulation pattern than hers. When responding to the client, the nurse integrates understanding of what information?

Fetal circulation carries highly oxygenated blood to vital areas first. Fetal circulation carries highly oxygenated blood to vital areas first while shunting it away from less vital ones. Fetal blood is not thicker than that of adults. Large volumes of oxygenated blood are not needed because the placenta essentially takes over the functions of the lung and liver during fetal life. Although fetal heart rates normally range from 120 to 160 beats per minute, circulation time is not doubled.

A nursing instructor is explaining the stages of fetal development to a group of nursing students. The instructor determines the session is successful after the students correctly choose which time period as representing the pre-embryonic stage?

From fertilization to the end of the second week after fertilization The pre-embryonic stage begins at fertilization and lasts through the end of the second week after fertilization. The embryonic stage begins approximately 2 weeks after fertilization and ends at the conclusion of the eighth week after fertilization. The fetal stage begins at 9 weeks after fertilization and ends at birth. There is no distinct stage recognized approximately 6 to 8 weeks after fertilization. This is part of the embryonic stage period.

A client with symptoms of pregnancy is having an ultrasound is to determine the gestation of the pregnancy. The nurse explains that the visualization of different developmental milestones correlates with the gestation of the pregnancy. Place the following developmental milestones in order, from earliest to latest, as they appear during the first trimester. Use all options.

Gestational sac Cardiac pulsation Spine formation Formation of limb buds A gestational sac appears between 4 to 5 weeks' gestation. Cardiac pulsation begins at 6 weeks' gestation, the spine is visible at 7 weeks' gestation, and evidence of four limb buds is present at 8 weeks' gestation.

A woman is confused after finding out the ultrasound results predict a different due date for the birth of her baby. Which factor should the nurse point out is most likely the reason for the miscalculation of the fetal age?

mistaking implantation bleeding for last menstrual period (LMP) The most common cause is implantation bleeding, which can occur as the blastocyst implants itself into the endometrium. This bleeding can be mistaken for a scanty menstrual period and can lead to miscalculation of fetal age by 2 weeks. The other choices might also contribute, especially the math miscalculation, but are not the primary reason.

A woman has just given birth to a healthy term newborn. Upon assessing the umbilical cord, the nurse would identify what findings as normal? Select all that apply.

one vein two arteries The normal umbilical cord contains one large vein and two small arteries.

Assessment for surfactant level is a primary estimation of fetal maturity. The purpose of surfactant is to:

prevent alveoli from collapsing on expiration. Surfactant is a phospholipid that reduces surface tension; it prevents alveoli from collapsing on expiration.

The placenta is the site where antibodies in the mother's blood pass into the fetal circulation. These antibodies give passive immunity to the fetus for several common childhood diseases. There are some infections for which the mother does not provide antibodies to the fetus. What infection is the fetus not protected from?

rubella The fetus does not receive immunity to rubella, cytomegalovirus (CMV), varicella, or measles. If the woman encounters these pathogens during her pregnancy, fetal infection may ensue.

A pregnant client asks the nurse how the fetus breathes if it is floating in the amniotic fluid. The best explanation by the nurse is:

the fetus receives oxygen through the umbilical vein. The fetal lungs are non-functional and are an organ of oxygenation during intrauterine life. There is no gas exchange occurring in the lungs. The fetus receives oxygenated blood through the umbilical vein. The umbilical artery removes carbon dioxide from the fetus. Oxygen from the maternal system diffuses across the placenta, but the maternal circulation is not responsible for fetal breathing.

The nurse is providing prenatal care to a young couple who is pregnant with their first child. In what period of development would the nurse explain to the couple that most congenital defects would occur?

the period of the embryo During the period of the embryo, which lasts until the eighth week after conception, the embryo is in what is called the critical phase of human development. During these weeks, all the organs and structures of the human are formed and are most susceptible to damage.

Implantation generally occurs at which place on the uterus?

the upper posterior surface Implantation occurs most commonly on the upper posterior surface of the uterus. This position allows the fetus to deliver before the placenta.

The purpose of a circulatory shunt, such as the ductus arteriosus, is to:

permit oxygenated blood to supply the most important fetal organs. The ductus arteriosus helps propel oxygenated blood quickly to the coronary arteries, brain, and kidneys.

While in utero, a fetus swallows many substances that are deposited in the fetal intestinal system as meconium. What problem can arise from this occurrence?

If the fetus becomes stressed, the meconium is released into the amniotic fluid, placing the fetus at risk for pneumonia. Infants develop meconium in their intestines; if they are stressed or hypoxic, the anal sphincter relaxes and meconium is passed into the amniotic fluid. This poses a danger to the fetus since they breathe in this fluid and swallow it. The meconium lines the lungs and respiratory passages, making it difficult for the infant to breathe once it is born.

A pregnant woman has a ruptured tubal pregnancy. What does the nurse anticipate the treatment will be?

Immediate surgical removal of the pregnancy and affected tube. If the tube ruptures, hemorrhage into the peritoneal cavity can lead to maternal death. Surgical removal of the affected tube and products of conception is the most common treatment. Because there is no way to transplant the embryo into the uterine cavity and continue the pregnancy, tubal pregnancies always result in the death of the embryo.

A woman being assessed by the nurse reports that she is 6 weeks' pregnant. If her report is accurate, when will the nurse predict the client conceived?

4 weeks ago The length of a pregnancy is more commonly measured from the first day of the last menstrual period (gestational age). Because ovulation and fertilization take place about 2 weeks after the last menstrual period, the ovulation age of the fetus is always 2 weeks less than the length of the pregnancy or the gestational age. Therefore this client conceived 4 weeks ago.

On what day during pregnancy does the embryo implant on the uterine surface?

8 days after ovulation After floating free in the uterine cavity for about 4 days, the zygote implants on the uterine surface on about the 22nd day; thereafter it is termed an embryo.

Which body system is most affected throughout the embryonic and fetal period by teratogens?

Central nervous system Whether the teratogen is ingested, injected, occurs through an infectious agent or is environmental, the CNS and brain are the body systems that are most seriously affected during this period.

After teaching a class on the various structures formed by the embryonic membranes, the nurse determines that the teaching was successful when the class identifies which structure as being formed by the ectoderm?

ears The ectoderm forms the structures of the special senses. The endoderm forms the structures of the respiratory and digestive systems. The mesoderm forms the structures of the skeletal system.

A woman at 15 weeks' gestation who works at a daycare center thinks she may have just been exposed to rubella at work. The client asks how this may affect her fetus. What is the best response the nurse can give?

"By the end of the eighth week all of the organ systems and major structures are present, so exposure to any teratogen can lead to birth defects. More assessments are needed." All organ systems are complete at 8 weeks gestation. During this time of organogenesis the growing structure is most vulnerable to invasion by teratogens.

The school nurse is presenting a lecture to adolescents to teach them how conception occurs. Which statement by the nurse would accurately describe this process?

"Conception usually occurs when the ovum is in the outer third of the fallopian tube." Conception usually occurs when the ovum is in the outer third of the fallopian tube (oviduct). Human life (conception) begins with the union of two cells: the ovum (female) and the sperm (male). At the time of conception, the sperm determines the sex. An ovum carries only one type of chromosome to determine sex: the X chromosome. A male sperm cell may carry either an X or Y sex chromosome. If a sperm cell carrying a Y chromosome fertilizes the ovum, a boy (XY) will result; if the sperm cell carries an X chromosome, the result will be a girl (XX).

A nursing instructor teaching a maternity course realizes a student needs more instruction upon overhearing the student make which of the following statements?

"Different sexual positions can determine the sex of the fetus." Some couples mistakenly believe that they can influence sex determination by using certain sexual positions, ingesting certain foods before intercourse, or timing sex to occur at specific times during the menstrual cycle. These beliefs are often rooted in folklore and not based on scientific principles.

After teaching a group of expectant mothers about how to best protect the fetus while in utero, which statement by a mother would best validate understanding of the teaching session?

"I will not take any medicines that the doctor has not prescribed without checking first." Expectant mothers must understand that they are not to take any medication, even over-the-counter ones, unless the doctor has approved them. Immunizations may also cross the placenta and adversely affect the fetus. Rubella is one that will devastate a fetus if it crosses the placenta, which will occur with immunization of the mother. Herbal products are also included in this warning.

A nursing instructor identifies a need for further instruction in regards to the three stages of fetal development when a nursing student makes which statement?

"The pre-embryonic stage begins approximately 2 weeks after fertilization." The three stages of human development are the pre-embryonic stage, which begins at fertilization and lasts through the end of the second week after fertilization; the embryonic stage, which begins approximately 2 weeks after fertilization and ends at the conclusion of the 8th week after fertilization; and the fetal stage, which begins approximately 9 weeks after fertilization and ends at birth.

A pregnant client is undergoing an amniocentesis in her third trimester and is worried why she is undergoing this procedure. Which statement by the nurse would best alleviate this client's anxieties?

"We want to be sure your baby's lungs are mature and this measures the development of the baby's lungs. The purpose of an amniocentesis is to determine if the lungs of the fetus are mature enough to support respirations outside the womb. Additionally, an amniocentesis is done for genetic testing for a variety of disorders. Telling the client that there might be a genetic disorder would only escalate the mother's concerns, not alleviate them. Telling the client the procedure is not dangerous or that the doctor will explain things after the amniocentesis does not address her concerns; rather, it minimizes them.

The pregnant client at 6 weeks' gestation asks the nurse if an ultrasound will reveal the sex of the fetus yet. What is the best response by the nurse?

"We will have to wait until the baby is 16 weeks' gestation to determine what the sex is." The sex of the baby can be determined by ultrasound at 16 weeks' gestation. An ultrasound at 6 and 8 weeks would be too early to determine the sex. An ultrasound at 20 weeks should confirm what was found at 16 weeks.

A couple comes into the family planning clinic inquiring how to best influence the gender of their next baby, since they have two boys and desire a girl this time. What advice would the nurse provide for this couple to assist in improving the odds of having a baby girl next time?

Although there are many beliefs regarding how to influence gender of babies, there is no scientific basis for any of them. Although there are many cultural and folklore beliefs concerning how to influence gender of babies, there are no scientific principles associated with them. Dietary changes, sexual positioning, and timing sex to occur at specific times during the menstrual cycle are not approved methods of gender determination.

The nursing instructor is leading a discussion on the process of implantation with a group of nursing students. The instructor determines the session is successful after the students correctly choose which explanation of a blastocyst?

An inner layer of cells that is separated from an outer layer of cells by a fluid-filled cavity The zygote divides rapidly, until it forms a ball of about 16 identical cells, which is then called a morula. The morula is then swept down the fallopian tube and into the uterus, a process that takes approximately 7 to 9 days. The lining of the uterus, or endometrium, has become rich in nutrients in preparation for the pregnancy. Just before the morula reaches the uterus, the cells begin to form layers—first an inner layer, then an outer layer that is around a fluid-filled space. This structure is called a blastocyst. As the structure continues to grow, the outer layer becomes the trophoblast, which will become the structures that nourish (the placenta) and protect the developing conceptus. The inner cell mass will become the embryo which will continue to grow and become the fetus.

The nursing instructor is presenting a session on the cellular division involved in the reproduction of human life. Which statement indicates the group's need for further education?

At ovulation, the gametes unite to form the cell that becomes the developing fetus. The female gamete is the ovum, and the male gamete is the sperm. At conception, not ovulation, the gametes unite to form the cell that eventually becomes the developing fetus. The other answers are correct.

The process of oogenesis begins before birth but is not complete until the childbearing years. At what point does the second meiotic division occur in this process?

At the time of fertilization by the sperm The first meiotic division occurs before ovulation, forming a secondary oocyte and a polar body. The polar body disintegrates due to lack of cytoplasm. This leads to the second meiotic division as the sperm fertilizes the oocyte. The second division occurs long before attachment to the uterine wall, and after the division producing the polar body and as the ovum leaves the ovary.

The nurse is caring for a 24-year-old client who is experiencing an ectopic pregnancy. What finding would cause the nurse to be most concerned and notify the doctor immediately?

Blood pressure of 92/64 Ectopic pregnancy occurs when the zygote implants outside the uterus. The most common site is in the fallopian tube, making it a tubal pregnancy. The tube dilates until it ruptures. Tubal rupture and hemorrhage can result in maternal death if undetected. The finding that is most disturbing and requires immediate notification of the doctor is the hypotension, which is indicative of blood loss and impending shock. Normal blood pressure for a pregnant woman is 120/70. The other findings are expected in an ectopic pregnancy and not emergent in nature.

The nursing instructor is presenting a class on the various classifications of twins. The instructor determines the session is successful after the students correctly choose which classification that indicates twins have separate amniotic sacs and placentas?

Diamniotic-dichorionic Diamniotic-dichorionic twins each develop in their own amniotic sac. Their placentas do not share any vessels. Monoamniotic-monochorionic twins have one amniotic cavity that they both share. "Biplacental" is not a type of twin.

The nurse is explaining the process of fertilization to a patient who has just learned of being pregnant. On which day during pregnancy should the nurse explain that the embryo implants on the uterine surface?

Eight to 10 days after fertilization Implantation, or contact between the growing structure and the uterine endometrium, occurs approximately 8 to 10 days after fertilization. Four days after fertilization the structure is a zygote. Implantation does not occur on the 14th day of a typical menstrual cycle or 10 days after the start of a menstrual flow.

During which stage of fetal development is exposure to teratogens most damaging?

Embryonic stage The most sensitive period of fetal development related to teratogens is during the embryonic period when the different body systems are developing. During the pre-embryonic stage, the fetal stage and the mitosis stage, the risk of teratogenic exposure is not as influential on the fetus.

A client asks the nurse to describe the difference between menstruation and implantation bleeding. Which statements should the nurse include in the description? Select all that apply.

Menstruation occurs when the ovum is not fertilized. Implantation bleeding occurs when the blastocyst burrows into the endometrium. Menstruation occurs 14 days after ovulation. Implantation bleeding occurs 7 to 10 days after fertilization. Menstruation is a cyclic bleeding that occurs when the ovum is not fertilized and begins about 14 days after ovulation. Implantation bleeding occurs 7 to 10 days after fertilization when the blastocyst burrows into the endometrium. Menstruation occurs in the ischemic phase, not the follicular phase of the uterine cycle. Menstruation occurs every 29 days, not every 8 days and varies from 21 to 35 days, not 1 to 14 days. Implantation bleeding is not as heavy as a menstrual period.

A client at the end of the first trimester asks what her fetus looks like. Which characteristics would the nurse tell the client are present in the fetus at this point in the pregnancy? Select all that apply.

Nail beds are forming on fingers and toes. Tooth buds are present. The baby's sex is distinguishable on outward appearance. The spinal cord is formed and fused at the midpoint. At the end of the first trimester or 12 weeks the fetus has nail beds forming on fingers and toes, tooth buds, and distinguishable outward sex. The spinal cord is formed and fused at the midpoint during the 4th week of pregnancy. Eyelids open and pupils react to light at 24 weeks (late in the second trimester).

Amniotic fluid is produced throughout the pregnancy by the fetal membranes. Amniotic fluid has four major functions. What is one of these functions?

Physical protection Amniotic fluid serves four main functions for the fetus: physical protection, temperature regulation, provision of unrestricted movement, and symmetrical growth.

A client comes to the clinic with concerns about her pregnancy. She is in her first trimester and is now experiencing moderate abdominal pain on the right side. What would be the nurse's first action?

Recommend an abdominal ultrasound to the doctor since this may be ectopic pregnancy. The nurse should recognize that abdominal pain is not normal during pregnancy and warrants investigation since ectopic pregnancy is a distinct possibility. An abdominal ultrasound would be best practice for this complaint. Dismissing her reports as normal is not a wise choice.

A woman calls the obstetrician's office and states that she is feeling nauseated and tired and suspects she may be pregnant. The nurse asks the woman when her last menstrual cycle was and is told that the woman had a light cycle three weeks ago. How would the nurse respond to this client?

Recommend that the woman come into the office for a pregnancy test or do a home pregnancy test. Women may experience a small amount of bleeding during the time of implantation and this scanty bleeding can be mistaken for a menstrual cycle and lead to miscalculation of the fetal dates. By doing a pregnancy test, the woman can determine if she is pregnant or not.

Spermatozoa begin their cellular division in what part of the male reproductive system?

Seminiferous tubules The male spermatozoa undergo the initial division in the seminiferous tubules within the testes. The other areas listed have no bearing on the development of spermatocytes.

A young mother in a prenatal class asks the nurse why there is amniotic fluid in the uterus with her baby. Which functions of the amniotic fluid should the nurse point out to the client? Select all that apply.

Shields the fetus against pressure or a blow to the mother's abdomen Protects the fetus from changes in temperature The most important purpose of amniotic fluid is to shield the fetus against pressure or a blow to the mother's abdomen. Because liquid changes temperature more slowly than air, it also protects the fetus from changes in temperature. And yet another function, it aids in muscular development, as amniotic fluid allows the fetus freedom to move. Finally, it protects the umbilical cord from pressure, protecting the fetal oxygen supply. It is progesterone that maintains the endometrial lining of the uterus. It is estrogen that contributes to mammary gland development in preparation for lactation and stimulates uterine growth to accommodate the developing fetus.

After teaching a class about conception, the nursing instructor asks the attendees to explain the process of fertilization. Which statements indicate the students need additional teaching? Select all that apply.

Sperm are viable for only about 48 hours after ejaculation. Sperm are able to fertilize the ovum up to 12 hours after ejaculation, and the ovum remains fertile for at least 24 hours after ovulation. Once the mature ovum is released (i.e., ovulation), fertilization must occur fairly quickly because an ovum is capable of fertilization for only about 24 to 48 hours. After that time, it atrophies and becomes nonfunctional. Because the functional life of a spermatozoon is also about 24 to 72 hours, the total critical time span during which sexual relations must occur for fertilization to be successful is from 3 days (72 hours) before until 2 days (48 hours) after ovulation.

A pregnant client at 10-weeks' gestation asks the nurse if the developing fetus can get infections. The nurse explains that until about 24 weeks' gestation the cytotrophoblast layer of cells protects the fetus from certain infections. The cytotrophoblast layer will protect against which of these infections? Select all that apply.

Syphilis Gonorrhea Group B streptococcus The cytotrophoblast layer has a secondary function to protect the growing embryo and fetus from certain infectious organisms, specifically bacteria such as spirochete of syphilis or Neisseria gonorrhea of gonorrhea and Group B streptococcus. The cytotrophoblast layer offers little protection against viral invasion at any point during pregnancy. Therefore, the developing pregnancy is at risk for infection from viruses that cause infections such as HIV and toxoplasmosis.

A multigravida client is concerned that she may deliver early. When asking the nurse what is the earliest her baby can be delivered and survive, which time frame would the nurse point out?

The end of the second trimester During the second trimester, fetal growth is significant. The fetus begins this trimester 3 inches long and weighing less than 1 oz (0.8 gm). By the end of the second trimester, the fetus is about 15 inches long and weighs more than 2 lbs (1000 gm). Major organs develop to the point that the fetus may survive (with help) outside the womb. The fetus would not be able to survive at the end of the first trimester. The end of the third trimester is the expected time of deliver. The fourth trimester involves the time after delivery.

The nurse is assessing a newborn infant for possible intrauterine growth restriction (IUGR). Which factor should the nurse analyze first to help determine if this diagnosis is accurate?

The ethnicity and stature of both the mother and father The nurse should first ensure it is truly IUGR and not related to other issues such as the ethnicity and stature of both the mother and father, as some ethnic groups commonly produce offspring that are smaller than others. The diet, certain teratogenic medications, and incorrect due dates may contribute to the correct diagnosis of IUGR.

What physiologic changes occur after birth when the cord is cut and clamped?

The infant takes its first breath and the lungs expand to increase blood oxygen levels. As the infant takes its first breath, the pulmonary resistance decreases and blood flow increases to the lungs, resulting in increased oxygenation of the infant's blood. The ductus venosus and the ductus arteriosus close, not the ductus ovale. The foramen ovale normally closes when the pressure gradient in the heart shift from higher pressure on the right side to higher pressure on the left side of the heart. The placenta is not immediately expelled once the infant takes its first breath.

While conducting a class for a group of pregnant women in their first trimester, one of the woman asks, "How is my baby's sex determined?" Which factors should the nurse include in the response? Select all that apply.

The male gamete is responsible for sex determination. The Y chromosome contains the genes for maleness. The female gamete has two X chromosomes. Because the sperm can have either an X or a Y chromosome, the male gamete is responsible for fetal sex determination. If the sperm Y chromosome combines with the female X chromosome, then the fetus will be a male. If both X chromosomes combined, then the fetus will be a female. Sex determination occurs at the time of fertilization not ovulation. The use of certain sexual positions and foods are old myths which are not true and do not effect the outcome. There are actually 23 total autosomes from the ovum and sperm which combine but only one from each which will determine the sex; the remaining chromosomes combine to determine other genetic qualities of the fetus.

A nursing student studying reproduction identifies which of the following statements to be correct?

Twenty-two of the 23 pairs of chromosomes are autosomes and the remaining pair is the sex chromosomes. The nucleus of each soma cell contains 46 chromosomes, arranged in 23 pairs. Each parent donates one chromosome of every pair. Each chromosome is composed of genes, which are segments of DNA that control hereditary traits. Twenty-two of the 23 pairs of chromosomes are autosomes, and the remaining pair, the sex chromosomes, determines an individual gender.

A nurse is conducting a prenatal class for expectant mothers and one of them asks how the placenta works. The nurse would explain that the placenta serves which purposes? Select all that apply.

The placenta provides nourishment for the fetus. It serves as an exchange site for oxygen and carbon dioxide. It serves as a barrier to some medications and hormones in the maternal blood supply. The placenta serves three main functions: transfer and exchange of substances such as nutrients and waste products; production of hormones; and to act as a barrier to certain substances. It does not provide physical protection for the fetus nor does it release insulin into the amniotic fluid for fetal use.

What purpose does amniotic fluid serve in fetal development? Select all that apply.

To allow the fetus to move about in-utero Reservoir for fetal urine and respiratory tract secretions Amniotic fluid serves as a protector for the fetus by allowing the fetus to move about in the uterus; the amniotic fluid physically protects the fetus. It also collects substances from the fetal gastrointestinal, urinary and respiratory tracts, which can be used for diagnostic studies.

A nursing instructor is discussing the various events that occur during a pregnancy. The instructor determines the session is successful after the students put the following events in the correct chronological order. Use all the options.

Union of an ovum and sperm Implantation of the zygote Formation of the placenta Heart begins beating Fetus kicks actively Fetus ready to be born The correct order is as follows: 1) union of an ovum and sperm (fertilization); 2) implantation of the zygote; 3) formation of the placenta; 4) heart begins beating; 5) fetus kicks actively; 6) fetus ready for birth.

Which actions would protect a fetus from exposure to environmental teratogens?

Use gloves when handling any chemicals. Environmental teratogens include X-rays and exposure to chemicals, so wearing gloves when coming in contact with any chemicals is advised. Cleaning cat litter boxes causes exposure to infectious agents. Alcohol consumption is never advised and a pregnant woman needs to seek approval for any medication she takes, but these are ingested teratogens.

During a clinical rotation at a prenatal clinic, a client asks a nurse what causes certain birth defects. The nurse replies that they can be caused by teratogens. What does the severity of the defects depend on? Select all that apply.

When during development the conceptus is exposed to the teratogen The particular teratogen to which the fetus is exposed A teratogen is a substance that causes birth defects. The severity of the defect depends on when during development the conceptus is exposed to the teratogen and the particular teratogenic agent to which the fetus is exposed.

A patient is to have an amniocentesis with ultrasound. What does the nurse explain to the patient that amniocentesis can determine? Select all that apply.

Whether the fetal lungs are mature enough to support respiration outside of the womb. For genetic testing. Amniotic fluid provides a great deal of information. During pregnancy, a procedure called an amniocentesis can obtain a sample of amniotic fluid. The practitioner can analyze the fluid to determine whether the fetal lungs are mature enough to support respiration outside of the womb. The fluid can also be used for genetic testing because the fluid contains fetal cells with fetal DNA.

Amniotic fluid does not grow stagnant because:

amniotic fluid is constantly formed by the amnion. Amniotic fluid is formed by the amnion; a main portion of it is swallowed by the fetus.

The nurse is conducting a presentation for a young adult community group about fetal development and pregnancy. The nurse determines that the teaching was successful when the group identifies that the sex of offspring is determined at which time?

at fertilization Sex determination occurs at the time of fertilization. Meiosis refers to cell division resulting in the formation of an ovum or sperm with half the number of chromosomes. The morula develops after a series of four cleavages following the formation of the zygote. Oogenesis refers to the development of a mature ovum, which has half the number of chromosomes.

During a prenatal class for a group of new mothers, the nurse is describing the hormones produced by the placenta. What hormones would the nurse include? Select all that apply.

estriol relaxin progestin human chorionic somatomammotropin Estriol, relaxin, progestin, and human chorionic somatomammotropin are secreted by the placenta. Prolactin is secreted after delivery for breast-feeding.

When preparing a presentation for a group of pregnant women about fetal circulation, the nurse would point out which structure is primarily responsible for ensuring that highly oxygenated blood reaches the fetal brain?

foramen ovale The ductus venosus provides a passageway for oxygenated blood from the umbilical vein to reach the inferior vena cava. The ductus arteriosus is a shunt that receives deoxygenated blood and transports it to the descending aorta. The umbilical vein carries oxygenated blood from the placenta to the fetus. The foramen ovale deflects blood from the vena cava into the left atrium, then left ventricle, into the ascending aorta and into the head and upper body so that the brain receives blood with the highest level of oxygenation.

An expectant mother is on heparin for previous blood clots and voicing concerns about how her medications will affect her baby. The nurse would inform the mother that:

heparin does not cross the placenta and is safe for her to take. Heparin is a medication that does not cross the placenta and therefore is safe to use during pregnancy. Not all medications cause fetal sequelae. It is not recommended to abruptly discontinue any medication without consulting the mother's health care provider and heparin is the safest anticoagulant for a pregnant woman to take.

The nursing instructor is illustrating the fetal circulation to a group of nursing students. The instructor determines the session is successful after the students correctly choose which main structure is most responsible for providing nutrition and removing waste from the fetus?

mother's blood The mother's blood is the structure most responsible for providing nutrition and removing waste from the fetus. The placenta and umbilical cord provide the passage for the blood to move back and forth. Without the mother's blood, the fetus would not be able to survive or get nutrition or send its waste products away. The amniotic fluid provides various functions but is not mainly responsible for providing nutrition or removing waste.

After teaching a class on the stages of fetal development, the nurse determines that the teaching was successful when the group identifies which stages? Select all that apply.

pre-embryonic embryonic fetal The three stages of fetal development are the pre-embryonic, embryonic, and fetal stage. Placental and umbilical are not stages of fetal development.

Which hormone(s) is secreted by the placenta during the pregnancy? Select all that apply.

progesterone estrogen human chorionic gonadotropin The placenta secretes hormones that help to sustain the pregnancy. These include progesterone, estrogen, human placental lactogen, and human chorionic gonadotropin. Testosterone is secreted by the male testes. Prolactin is secreted by the anterior pituitary gland.

What medication should the nurse advise a woman to discontinue prior to becoming pregnant because it will damage the developing dental and osseous tissue in the fetus?

tetracycline Tetracycline may damage the developing dental and osseous tissue in the fetus.

A fertilized ovum is known as which structure?

zygote A fertilized ovum is known as a zygote and is the beginning of potential individual human development. The developing human organism is known as an embryo from the time it implants on the uterine wall until the eighth week after inception and as a fetus from the beginning of the ninth week after fertilization through birth. The chorion is the outermost cell layer that surrounds the embryo and fluid cavity.