Chapter 9 quizlet

Fertilization

(also referred to as conception and impregnation): union of ovum and spermatozoon usually occurs in the outer third of a Fallopian tube (ampullar portion)

placentas are graded as:

0: between 12 and 24 weeks 1: 30 to 32 weeks 2: 36 weeks 3: 38 weeks (Because fetal lungs are apt to be mature by 38 weeks, a grade 3 placenta suggests the fetus is mature.)

fertilization depends on what 3 factors

1. Equal maturation of both sperm and ovum 2. Ability of the sperm to reach the ovum 3. Ability of the sperm to penetrate the zona pellucida and cell membrane and achieve fertilization

what is the most important purposes of amniotic fluid?

1. 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. 2. aids in muscular development, as amniotic fluid allows the fetus freedom to move. 3. protects the umbilical cord from pressure, thus protecting the fetal oxygen supply.

How long is the ovum capable of fertilization?

24 hours (48 hours at most) after that, it atrophies and becomes nonfunctional

at term, how much urine can be excreted

500 ml/day

Biophysical Profile

A biophysical profile combines five parameters (i.e., fetal reactivity, fetal breathing movements, fetal body movement, fetal tone, and amniotic fluid volume) into one assessment

Biophysical profiles may be done as often as daily during a high-risk pregnancy. The fetal scores are as follows:

A score of 8 to 10 means the fetus is considered to be doing well. A score of 6 is considered suspicious. A score of 4 denotes a fetus potentially in jeopardy.

Mrs. Smith asks the nurse to compute her expected due date. Based on the fact that her last menstrual flow began on July 20, which due date would the nurse estimate?

A. April 27

Amniotic fluid (obtained through amniocentesis) can be analyzed for:

AFP, Acetylcholinesterase, Bilirubin determination, Chromosome analysis, Color (should be like watery yellow), Fibronectin, Inborn errors of metabolism, Lecithin and sphingomyelin ratio, Phosphatidylglycerol and desaturated phosphatidylcholine

chorionic vili

As early as the 11th or 12th day after fertilization, miniature villi, resembling probing fingers and reach out from the trophoblast cells into the uterine endometrium to begin formation of the placenta.

Placental Circulation

As early as the 12th day of pregnancy, maternal blood begins to collect in the intervillous spaces of the uterine endometrium surrounding the chorionic villi. By the third week, oxygen and other nutrients such as glucose, amino acids, fatty acids, minerals, vitamins, and water osmose from the maternal blood through the cell layers of the chorionic villi into the villi capillaries. From there, nutrients are transported to the developing embryo.

cephalocaudal

As soon as conception has taken place, development proceeds in a cephalocaudal (head-to-tail) direction; that is, head development occurs first and is followed by development of the middle and, finally, the lower body parts. This pattern of development continues after birth as shown by the way infants are able to lift up their heads approximately 1 year before they are able to walk.

respiratory system

At the third week of intrauterine life, the respiratory and digestive tracts exist as a single tube. Like all body tubes, initially, this forms as a solid structure, which then canalizes By the end of the fourth week, a septum begins to divide the esophagus from the trachea. At the same time, lung buds appear on the trachea.

Which of the following nursing interventions is appropriate when preparing a woman for an amniocentesis?

B. Be certain she knows that there is a slight risk of complication, such as premature labor, from amniocentesis. Rationale: Amniocentesis carries a slight risk of beginning labor. The woman should not hold her breath because that depresses the diaphragm, shifts the contour of the uterus, and may shift the location of the placenta to the chosen needle insertion site. The bladder should be emptied to avoid accidental puncture.

How long does a spermatozoon have to fertilize?

Because the functional life of a spermatozoon is also about 48 hours, possibly as long as 72 hours, the total critical time span during which sexual relations must occur for fertilization to be successful is about 72 hours (48 hours before ovulation plus 24 hours afterward).

structure of chorionic vili

Chorionic villi have a central core consisting of connective tissue and fetal capillaries surrounded by a double layer of cells, which produce various placental hormones, such as hCG, somatomammotropin (human placental lactogen [hPL]), estrogen, and progesterone. The middle layer, the cytotrophoblast or Langhans' layer, appears to have a second function to protect the growing embryo and fetus from certain infectious organisms such as the spirochete of syphilis early in pregnancy

A fetus is able to maintain blood circulation in utero by the presence of circulatory shunts. The nurse understands this is because the ductus arteriosus in utero shunts blood in which direction?

D. Pulmonary artery to the aorta Rationale: Because the fetal lungs are not inflated, blood must be diverted past them. The ductus arteriosus helps to do this by shunting blood from the pulmonary artery to the aorta.

what body parts are formed during the Mesoderm

Supporting structures of the body (connective tissue, bones, cartilage, muscle, ligaments, and tendons) Upper portion of the urinary system (kidneys and ureters) Reproductive system Heart, lymph, and circulatory systems and blood cells

what is the proper measurement for amniotic fluid

The amniotic fluid index is measured, and it should be at least 5 cm. The vertical pocket of amniotic fluid should be greater than 2 cm

Digestive system

The digestive tract separates from the respiratory tract at about the fourth week of intrauterine life and, after that, begins to grow extremely rapidly.

Age of viability

The earliest age at which fetuses survive if they are born is generally accepted as 24 weeks or at the point a fetus weighs more than 500-600 g

endocrine system

The function of endocrine organs begins along with neurosystem development. The fetal pancreas produces insulin needed by the fetus (insulin is one of the few substances that does not cross the placenta from the mother to the fetus). The thyroid and parathyroid glands play vital roles in fetal metabolic function and calcium balance. The fetal adrenal glands supply a precursor necessary for estrogen synthesis by the placenta.

End of Fourth Gestational Week

The length of the embryo is about 0.75 cm; weight is about 400 mg. The spinal cord is formed and fused at the midpoint. The head is large in proportion and represents about one third of the entire structure. The rudimentary heart appears as a prominent bulge on the anterior surface. Arms and legs are bud-like structures; rudimentary eyes, ears, and nose are discernible.

End of 16th Gestational Week

The length of the fetus is 10 to 17 cm; weight is 55 to 120 g. Fetal heart sounds are audible by an ordinary stethoscope. Lanugo is well formed. Both the liver and pancreas are functioning. The fetus actively swallows amniotic fluid, demonstrating an intact but uncoordinated swallowing reflex; urine is present in amniotic fluid. Sex can be determined by ultrasonography.

End of 20th Gestational Week

The length of the fetus is 25 cm; weight is 223 g. Spontaneous fetal movements can be sensed by the mother. Antibody production is possible. Hair, including eyebrows, forms on the head; vernix caseosa begins to cover the skin. Meconium is present in the upper intestine. Brown fat, a special fat that aids in temperature regulation, begins to form behind the kidneys, sternum, and posterior neck. Passive antibody transfer from mother to fetus begins. Definite sleeping and activity patterns are distinguishable as the fetus develops biorhythms that will guide sleep/wake patterns throughout life.

End of 24th Gestational Week (Second Trimester)

The length of the fetus is 28 to 36 cm; weight is 550 g. Meconium is present as far as the rectum. Active production of lung surfactant begins. Eyelids, previously fused since the 12th week, now open; pupils react to light. Hearing can be demonstrated by response to sudden sound. When fetuses reach 24 weeks, or 500 to 600 g, they have achieved a practical low-end age of viability if they are cared for after birth in a modern intensive care nursery.

End of 28th Gestational Week

The length of the fetus is 35 to 38 cm; weight is 1,200 g. Lung alveoli are almost mature; surfactant can be demonstrated in amniotic fluid. Testes begin to descend into the scrotal sac from the lower abdominal cavity. The blood vessels of the retina are formed but thin and extremely susceptible to damage from high oxygen concentrations (an important consideration when caring for preterm infants who need oxygen).

End of 32nd Gestational Week

The length of the fetus is 38 to 43 cm; weight is 1,600 g. Subcutaneous fat begins to be deposited (the former stringy, "little old man" appearance is lost). Fetus responds by movement to sounds outside the mother's body. An active Moro reflex is present. Iron stores, which provide iron for the time during which the neonate will ingest only breast milk after birth, are beginning to be built. Fingernails reach the end of fingertips.

End of 36th Gestational Week

The length of the fetus is 42 to 48 cm; weight is 1,800 to 2,700 g (5 to 6 lb). Body stores of glycogen, iron, carbohydrate, and calcium are deposited. Additional amounts of subcutaneous fat are deposited. Sole of the foot has only one or two crisscross creases compared with a full crisscross pattern evident at term. Amount of lanugo begins to diminish. Most fetuses turn into a vertex (head down) presentation during this month.

End of 40th Gestational Week (Third Trimester)

The length of the fetus is 48 to 52 cm (crown to rump, 35 to 37 cm); weight is 3,000 g (7 to 7.5 lb). Fetus kicks actively, sometimes hard enough to cause the mother considerable discomfort. Fetal hemoglobin begins its conversion to adult hemoglobin. Vernix caseosa starts to decrease after the infant reaches 37 weeks gestation and may be more apparent in the creases than the covering of the body as the infant approaches 40 weeks or more gestational age. Fingernails extend over the fingertips. Creases on the soles of the feet cover at least two thirds of the surface.

End of 12th Gestational Week (First Trimester)

The length of the fetus is 7 to 8 cm; weight is about 45 g. Nail beds are forming on fingers and toes. Spontaneous movements are possible, although they are usually too faint to be felt by the mother. Some reflexes, such as the Babinski reflex, are present. Bone ossification centers begin to form. Tooth buds are present. Sex is distinguishable on outward appearance. Urine secretion begins but may not yet be evident in amniotic fluid. The heartbeat is audible through Doppler technology.

End of Eighth Gestational Week

The length of the fetus is about 2.5 cm (1 in.); weight is about 20 g. Organogenesis is complete. The heart, with a septum and valves, beats rhythmically. Facial features are definitely discernible; arms and legs have developed. External genitalia are forming, but sex is not yet distinguishable by simple observation. The abdomen bulges forward because the fetal intestine is growing so rapidly. A sonogram shows a gestational sac, which is diagnostic of pregnancy

integumentary system

The skin of a fetus appears thin and almost translucent until subcutaneous fat begins to be deposited underneath it at about 36 weeks

Naegele's Rule

To calculate the date of birth by this rule, count backward 3 calendar months from the first day of a woman's last menstrual period and add 7 days. For example, if the last menstrual period began May 15, you would count back 3 months (April 15, March 15, February 15) and add 7 days, to arrive at the predicted date of birth as February 22.

what is normal for the nonstresstest

When the fetus moves, the fetal heart rate should increase approximately 15 beats/min and remain elevated for 15 seconds. It should decrease to its average rate again as the fetus quiets (Fig. 9.10C). If no increase in beats per minute is noticeable on fetal movement, further testing may be necessary to rule out poor oxygen perfusion of the fetus. A nonstress test usually is done for 20 minutes. The test is said to be reactive (healthy) if two accelerations of fetal heart rate (by 15 beats or more) lasting for 15 seconds occur after movement within the time period. if a 20 min passes w/o movement it could be from the baby sleeping

Meconium

a collection of cellular wastes, bile, fats, mucoproteins, mucopolysaccharides, and portions of the vernix caseosa, accumulates in the intestines as early as the 16th week. Meconium is sticky in consistency and appears black or dark green

amniotic membrane

a dual-walled sac with the chorion as the outmost part and the amnion as the innermost part. The two fuse together as the pregnancy progresses, and by term, they appear to be a single sac. They have no nerve supply, so when they spontaneously rupture at term or are artificially ruptured via a procedure, neither the pregnant woman nor fetus experiences any pain

Surfactant

a phospholipid substance, is formed and excreted by the alveolar cells of the lungs beginning at approximately the 24th week of pregnancy. This decreases alveolar surface tension on expiration, preventing alveolar collapse and improving the infant's ability to maintain respirations in the outside environment at birth Surfactant has two components: lecithin and sphingomyelin

how much does the placenta weigh at term

a placenta weighs 400 to 600 g (1 lb), one-sixth the weight of the newborn. If a placenta is smaller than this, it suggests circulation to the fetus may have been compromised and/or inadequate. A placenta bigger than this also may indicate circulation to the fetus was threatened because it suggests the placenta was forced to spread out in an unusual manner to maintain a sufficient blood supply.

what can pass through the placenta

almost all drugs are able to cross into the fetal circulation, it is important that a woman take no nonessential drugs (including alcohol and nicotine) during pregnancy

what is a zygote Called once implanted

an embryo

Magnetic resonance imaging (MRI)

another way to assess a growing fetus. Because the technique apparently causes no harmful effects to the fetus or woman, MRI has the potential to replace or complement ultrasonography as a fetal assessment technique because it can identify structural anomalies or soft tissue disorders

how early can the doppler detect a heartbeat

as early as the 10th to 12th week of pregnancy

oligohydramnios

as soon as the fetal kidneys become active, fetal urine adds to the quantity of the amniotic fluid. A disturbance of kidney function, therefore, may cause oligohydramnios or a reduction in the amount of amniotic fluid. Oligohydramnios can be detected by ultrasound.

where should the funds be at 20 weeks

at the umbilicus

braxton Hicks contractions

barely noticeable uterine contractions present from about the 12th week of pregnancy on, aid in maintaining pressure in the intervillous spaces by closing off the uterine veins momentarily with each contraction.

Fetal heart sounds

can be heard and counted as early as the 10th to 11th week of pregnancy by the use of an ultrasound Doppler technique This is done routinely at every prenatal visit past 10 weeks.

reproductive system

child's sex is determined at the moment of conception by a spermatozoon carrying an X or a Y chromosome and can be ascertained as early as 8 weeks by chromosomal analysis or analysis of fetal cells in the mother's bloodstream.

chorionic membrane

chorionic villi on the medial surface of the trophoblast gradually thin until they become this. It is the outer most fetal membrane

Implantation

contact between growing structure and uterine endometrium, approximately 8 to 10 days after fertilization usually occurs high in the uterus on the posterior surface

stages of implantation

day 1- fertilization day 2- zygote day 3- morula day 4- blastocyst day 8-10- embryo

amniotic fluid

ever becomes stagnant because it is constantly being newly formed and absorbed by direct contact with the fetal surface of the placenta. The major method of absorption, however, happens within the fetus. Because the fetus continually swallows the fluid, it is absorbed from the fetal intestine into the fetal bloodstream. From there, it goes to the umbilical arteries and to the placenta and is exchanged across the placenta to the mother's bloodstream. At term, the amount of amniotic fluid has grown so much it ranges from 800 to 1,200 ml.

How is the umbilical cord formed?

formed from the fetal membranes, the amnion and chorion, and provides a circulatory pathway that connects the embryo to the chorionic villi of the placenta.

Ovum

from ovulation to fertilization

Human Placental Lactogen (Human Chorionic Somatomammotropin)

has growth-promoting and lactogenic (i.e., milk-producing) properties. produced by the placenta beginning as early as the sixth week of pregnancy, increasing to a peak level at term. promotes mammary gland growth regulates maternal glucose, protein, and fat levels

Uterine perfusion and placental circulation are most efficient when the mother lies on her _____ side

left side this position lifts the uterus away from the inferior vena cava, preventing blood from becoming trapped in the woman's lower extremities. If the woman lies on her back and the weight of the uterus compresses on the vena cava, known as vena cava syndrome, placental circulation can be so sharply reduced that supine hypotension can occur

nonstress test

measures the response of the fetal heart rate to fetal movement. Position the woman and attach both a fetal heart rate and a uterine contraction monitor. Instruct the woman to push the button attached to the monitor (similar to a call bell) whenever she feels the fetus move. This will create a dark mark on the paper tracing at these times.

Progesterone

progesterone is necessary to maintain the endometrial lining of the uterus during pregnancy. It is present in maternal serum as early as the fourth week of pregnancy as a result of the continuation of the corpus luteum. After placental production begins (at about the 12th week), the level of progesterone rises progressively during the remainder of the pregnancy. This hormone also appears to reduce the contractility of the uterus during pregnancy, thus preventing premature labor.

what is the rate of blood flow through an umbilical cord

rapid (350 ml/min at term). The adequacy of blood flow (blood velocity) through the cord, as well as both systolic and diastolic cord pressure, can be determined by ultrasound examination. Counting the number of coils in the cord may be used as a prediction of healthy fetal growth, as hypocoiling is associated with maternal hypertension and hypercoiling is associated with respiratory distress in the newborn

vernix caseosa

ream cheese-like substance,which is important for lubrication and for keeping the skin from macerating in utero.

Rhythm Strip Testing

refers to an assessment of fetal well-being and assesses the fetal heart rate for a normal baseline rate. For this, help the woman into a semi-Fowler's position (either in a comfortable lounge chair or on an examining table or bed with an elevated backrest) to prevent her uterus from compressing the vena cava and causing supine hypotension syndrome during the test. Attach an external fetal heart rate monitor abdominally (Fig. 9.10A). Record the fetal heart rate for 20 minutes.

Placenta and membranes

serve as the fetal lungs, kidneys, and digestive tract in utero as well as help provide protection for the fetus, begin growth in early pregnancy in coordination with embryo growth. The placenta grows from a few identifiable trophoblastic cells at the beginning of pregnancy to an organ 15 to 20 cm in diameter and 2 to 3 cm in depth, covering about half the surface area of the internal uterus at term

where should the fundus be at 12 weeks

symphysis pubis

McDonald's rule

symphysis-fundal height measurement (although, again, not documented to be thoroughly reliable), is an easy method of determining midpregnancy growth. Typically, tape measurement from the notch of the symphysis pubis to over the top of the uterine fundus as a woman lies supine is equal to the week of gestation in centimeters between the 20th and 31st weeks of pregnancy

eventh week of life respiratory

the diaphragm does not completely divide the thoracic cavity from the abdomen. This causes lung buds to extend down into the abdomen, reentering the chest only as the chest's longitudinal dimension increases and the diaphragm becomes complete (at the end of the seventh week). If the diaphragm fails to close completely, the stomach, spleen, liver, or intestines may be pulled up into the thoracic cavity. This causes the child to be born with intestine present in the chest , compromising the lungs and perhaps displacing the heart

decidua

the endometrium of the uterus during pregnancy discarded after birth of the child

Zygote

the fertilized egg; it enters a 2-week period of rapid cell division and develops into an embryo Because the spermatozoon and ovum each carried 23 chromosomes (22 autosomes and 1 sex chromosome), the fertilized ovum has 46 chromosomes If an X-carrying spermatozoon entered the ovum, the resulting child will have two X chromosomes and will be assigned female at birth (XX). If a Y-carrying spermatozoon fertilized the ovum, the resulting child will have an X and a Y chromosome and will be assigned male at birth (XY).

fetoscopy

the fetus is visualized by inspection through a fetoscope (an extremely narrow, hollow tube inserted by amniocentesis technique), can be yet another way to assess fetal well-being. This method allows direct visualization of both the amniotic fluid and the fetus The main reasons the procedure is used are to: Confirm the intactness of the spinal column. Obtain biopsy samples of fetal tissue and fetal blood samples. Determine meconium staining is not present. Perform elemental surgery

what can the baby be vulnerable to during organogenesis

the growing structure is most vulnerable to invasion by teratogens (i.e., any factor that affects the fertilized ovum, embryo, or fetus adversely, such as a teratogenic medicine; an infection such as toxoplasmosis; cigarette smoking; or alcohol ingestion)

Nervous system

the nervous system begins to develop extremely early in pregnancy. he neurologic system seems particularly prone to insult during the early weeks of the embryonic period and can result in neural tube disorders, such as a meningocele , especially if there is lack of folic acid (which is contained in green leafy vegetables and pregnancy vitamins) All during pregnancy and at birth, the system is vulnerable to damage if anoxia should occur.

where should the fundus be at 36 weeks

xiphiod process

Estrogen

Estrogen contributes to the woman's mammary gland development in preparation for lactation and stimulates uterine growth to accommodate the developing fetus.

Maternal Serum α-Fetoprotein

FP is a substance produced by the fetal liver that can be found in both amniotic fluid and maternal serum (maternal serum α-fetoprotein [MSAFP]). The level is abnormally high if the fetus has an open spinal or abdominal wall defect because the open defect allows more AFP to enter the mother's circulation than usual. Although the reason is unclear, the level is low if the fetus has a chromosomal defect such as Down syndrome.

Daily Fetal Movement Count (Kick Counts)

Fetal movement that can be felt by the mother (quickening) occurs at approximately 18 to 20 weeks of pregnancy and peaks in intensity at 28 to 38 weeks. After that time, a healthy fetus moves with a degree of consistency at about 10 times per hour.

Vibroacoustic Stimulation

For acoustic (sound) stimulation, a specially designed acoustic stimulator is applied to the mother's abdomen to produce a sharp sound of approximately 80 dB at a frequency of 80 Hz, thus startling and waking the fetus

Fetus

From 5-8 weeks until term

Embryo

From implantation to 5-8 weeks

Immune system

Immunoglobulin (Ig) G maternal antibodies cross the placenta into the fetus as early as the 20th week and certainly by the 24th week of intrauterine life to give a fetus temporary passive immunity against diseases for which the mother has antibodies. A fetus only becomes capable of active antibody production late in pregnancy.

biparietal diameter

In 80% of pregnancies in which the biparietal diameter of the fetal head is 8.5 cm or greater, it can be predicted the infant will weigh more than 2,500 g (5.5 lb) at birth or is at a fetal age of 40 weeks.

Percutaneous Umbilical Blood Sampling

Percutaneous umbilical blood sampling (PUBS; also called cordocentesis or funicentesis) is the aspiration of blood from the umbilical vein for analysis. a thin needle is inserted by amniocentesis technique into the uterus and is then guided by ultrasound until it pierces the umbilical vein. A sample of blood is then removed for blood studies, such as a complete blood count, direct Coombs test, blood gases, and karyotyping.

quickening

Movements of the fetus that can be felt by the mother

Absent

No peak-to-trough range is detectable.

lanugo

Skin is covered by soft downy hairs (lanugo) that serve as insulation to preserve warmth in utero

Fetal Gender

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

urinary system

Although rudimentary kidneys are present as early as the end of the fourth week of intrauterine life, the presence of kidneys does not appear to be essential for life before birth because the placenta clears the fetus of waste products. Urine, however, is formed by the 12th week and is excreted into the amniotic fluid by the 16th week of gestation.

Minimal

An amplitude range is detectable but the rate is 5 beats/min or fewer.

Moderate or normal

An amplitude range is detectable; rate is 6 to 25 beats/min.

Marked

An amplitude range is detectable; rate is greater than 25 beats/min

What does the umbilical cord contain?

An umbilical cord contains only one vein (carrying blood from the placental villi to the fetus) and two arteries (carrying blood from the fetus back to the placental villi). The number of veins and arteries in the cord is always assessed and recorded at birth because about 1% to 5% of infants are born with a cord that contains only a single vein and artery. Of these infants, 15% to 20% are found to have accompanying chromosomal disorders or congenital anomalies, particularly of the kidney and heart

how does fetal circulation occur

Blood arriving at the fetus from the placenta is highly oxygenated. This blood enters the fetus through the umbilical vein (which is still called a vein even though it carries oxygenated blood because the direction of the blood is toward the fetalheart). Specialized structures present in the fetus then shunt blood flow to first supply the most important organs of the body: the liver, heart, kidneys, and brain. Blood flows from the umbilical vein to the ductus venosus, an accessory vessel that discharges oxygenated blood into the fetal liver, and then connects to the fetal inferior vena cava so oxygenated blood is directed to the right side of the heart. Because there is no need for the bulk of blood to pass through the lungs, the bulk of this blood is shunted as it enters the right atrium into the left atrium through an opening in the atrial septum called the foramen ovale. From the left atrium, it follows the course of adult circulation into the left ventricle, then into the aorta, and out to body parts. A small amount of blood that returns to the heart via the vena cava does leave the right atrium by the adult circulatory route; that is, through the tricuspid valve into the right ventricle and then into the pulmonary artery and lungs to service the lung tissue. However, the larger portion of even this blood is shunted away from the lungs through an additional structure, the ductus arteriosus, directly into the descending aorta. As the majority of blood cells in the aorta become deoxygenated, blood is transported from the descending aorta through the umbilical arteries (which are called arteries because they carry blood away from the fetal heart) back through the umbilical cord to the placental villi, where new oxygen exchange takes place.

what body parts are formed during the Ectoderm

Central nervous system (brain and spinal cord) Peripheral nervous system Skin, hair, nails, and tooth enamel Sense organs Mucous membranes of the anus, mouth, and nose Mammary glands

Nuchal Translucency

Children with a number of chromosome anomalies have unusual pockets of fat or fluid present in their posterior neck, which show on sonograms as nuchal translucency.

Conceptus

Developing embryo and placental structures throughout pregnancy

Ultrasonography

Diagnose pregnancy as early as 6 weeks gestation. Confirm the presence, size, and location of the placenta and amniotic fluid. Establish a fetus is growing and has no gross anomalies such as hydrocephalus; anencephaly; or spinal cord, heart, kidney, and bladder concerns. Establish the sex if a penis is revealed. Establish the presentation and position of the fetus. Predict gestational age by measurement of the biparietal diameter of the head or crown-to-rump measurement. Discover complications of pregnancy retained placenta

Doppler Umbilical Velocimetry

Doppler ultrasonography measures the velocity at which red blood cells in the uterine and fetal vessels travel

normal results for Vibroacoustic Stimulation

During a standard nonstress test, if a spontaneous acceleration has not occurred within 5 minutes, apply a single 1- to 2-second sound stimulation to the lower abdomen. This can be repeated again at the end of 10 minutes if no further spontaneous movement occurs, so two movements within the 20-minute window can be evaluated.

musculoskeletal system

During the first 2 weeks of fetal life, cartilage prototypes provide position and support to the fetus. Ossification of this cartilage into bone begins at about the 12th week and continues all through fetal life and into adulthood.

hydramnios

If for any reason the fetus is unable to swallow (esophageal atresia or anencephaly are the two most common reasons), excessive amniotic fluid will occur

Normal length of umbilical cord

It is about 53 cm (21 in.) in length at term and about 2 cm (0.75 in.) thick.

what is the function of the umbilical cord

Its function is to transport oxygen and nutrients to the fetus from the placenta and to return waste products from the fetus to the placenta.

what body parts are formed during the Endoderm

Lining of pericardial, pleura, and peritoneal cavities Lining of the gastrointestinal tract, respiratory tract, tonsils, parathyroid, thyroid, and thymus glands Lower urinary system (bladder and urethra)

what are the three time periods of fetal growth and development

Pre-embryonic (first 2 weeks, beginning with fertilization) embryonic (weeks 3-8) Fetal (week 8-birth)

Maternal Serum for Pregnancy-Associated Plasma Protein A

Pregnancy-associated plasma protein A (PAPP-A) is a protein secreted by the placenta; low levels in maternal blood are associated with fetal chromosomal anomalies, including trisomies 13, 18, and 21 or small-for-gestational-age (SGA) babies. A high PAPP-A level may predict an LGA baby.

Quadruple Screening

Quadruple screening analyzes four indicators of fetal health: AFP, unconjugated estriol (UE; an enzyme produced by the placenta that estimates general well-being), hCG (also produced by the placenta), and inhibin A (a protein produced by the placenta and corpus luteum associated with Down syndrome).

If the woman has Rh-negative blood

Rho(D) immune globulin (RhIG; RhoGAM) is administered after the procedure to prevent fetal isoimmunization or help ensure maternal antibodies will not form against any placental red blood cells that might have accidentally been released into the maternal bloodstream during the procedure.

placental blood exchange

To provide enough blood for exchange, the rate of uteroplacental blood flow in pregnancy increases from about 50 ml/min at 10 weeks to 500 to 600 ml/min at term