Maternal And Pedia PDF

Summary

This document is a collection of notes on medical genetics and pediatrics. It covers topics such as surveillance of high-risk pregnancies, genetics and genetic counseling, and chromosomal abnormalities, along with their prevalence. It also includes information on inheritance patterns and various genetic disorders.

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6 Staff need to be trained to recognize risk Cytogenetics - Is the study of chromosomes factors by light microscopy and the 7 Need the motivation to persuade women method by which chromosom...

6 Staff need to be trained to recognize risk Cytogenetics - Is the study of chromosomes factors by light microscopy and the 7 Need the motivation to persuade women method by which chromosomal and family aberrations are identified SURVEILLANCE OF HIGH RISK NATURE OF INHERITANCE PREGNANCY GENES are the basic units of heredity Maternal - Medical, obstetrical, nursing that determine both the monitoring history physical and cognitive - Environmental and personal risk characteristics of people. It is factors composed of segments of - Prenatal physical examination DNA, they are woven into - Sudden weight gain strands in the nucleus. - Roll over test: 28-32 weeks AOG CHROMOSOMES are threadlike structures of - Urine test for albumin nucleic acids and protein - Urinalysis found in the nucleus of most - Hemoglobin determination living cells, carrying genetic - HbSAg information in the form of Fetal - Family history genes monitoring - Leopold’s maneuver and fundic height measurement In humans, each cell, except - Maternal serum screening for for the sperm and ovum, alpha fetoprotein contains 46 chromosomes - Ultrasound (22 pair of autosomes and 1 pair of sex chromosomes). GENETICS AND GENETIC COUNSELLING Although the number three leading cause of infant Spermatozoa and ova each mortality is chromosomal abnormalities, limited carry only half of the attention has been given to birth defects and other chromosome number, or 23 genetic conditions (http://www.doh.gov.ph/mortality). chromosomes. For each Table 2 describes the prevalence of congenital chromosome in the sperm disorders by cause in the Philippines. This situation cell, there is a like has been aggravated by the small number of chromosome of similar size geneticists and genetic counselors who can provide and shape and function genetic diagnosis, management, and counseling (autosome, or homologous services to patients. The delivery of medical genetic chromosome) in the ovum. services thus remains a challenge in both private and Because genes are always public sectors. located at fixed positions on chromosomes, two like CAUSES ESTIMATED genes (alleles) for every trait PREVALENCE are represented in the ovum 1. Dominant single-gene and sperm on autosomes. 7 The one chromosome in disorders which this does not occur is 2. Recessive single gene 2.3 the chromosome for disorder determining gender. 3. X-linked recessive 1.3 single-gene disorders If the sex chromosomes are 4. Chromosomal disorder 4.2 both type X (large symmetric) 5. Malformations 63.9 in the zygote formed from the Table 2. prevalence of congenital disorder by cause union of a sperm and ovum, in the Philippines the individual is female. If one sex chromosome is an X and Inherited or genetic disorders are disorders that can one a Y (a smaller type), the be passed from one generation to the next. They individual is a male. result from some disorder in gene or chromosome structure and occur in 5% to 6% of newborns. A person’s phenotype refers to his or her outward Genetics - Is the study of heredity and the appearance or the variation of inherited expression of genes. characteristics JAZILLE F. BATCH 2026 A person’s genotype refers to carrier free (i.e., carrying no affected gene for his or her actual gene the disorder). composition. It is impossible - Two heterozygous people with a dominantly to predict a person’s inherited disorder are unlikely to choose each genotype from the other as reproductive partners. If they do phenotype, or outward there would be only a 25% chance of a child’s appearance. being disease and carrier free, a 50% chance that the child would have the disorder as both A person’s genome is the parents do, and a 25% chance that a child complete set of genes would be homozygous dominant (i.e., have present o A normal genome two dominant disorder genes), a condition is abbreviated as 46XX or that probably would be incompatible with life 46XY. (Figure 2) MENDELIAN INHERITANCE: Dominant and Recessive Patterns The principles of genetic inheritance of disease are the same as those that govern genetic inheritance of other physical characteristics, such as eye or hair color. These principles were discovered and described by Gregor Mendel, an Austrian naturalist, in the 1800s and are known as mendelian laws. Homozygous are two like chromosomes (one traits from the mother and one from the father) Heterozygous occur when the genes differ (a In assessing family genograms (maps of family traits healthy gene from the mother relationships) for the incidence of inherited disorders, and an unhealthy gene from the a number of common findings are usually discovered father, or vice versa when a dominantly inherited pattern is present in a Homozygous An individual with two family (Fig. 3) : dominant homozygous genes for a dominant trait one of the parents of a child with the disorder Homozygous an individual with two genes for a a also will have the disorder (a vertical recessive recessive trait transmission picture) The sex of the affected individual is Dominant genes are always expressed in b unimportant in terms of inheritance preference to the recessive genes. There is usually a history of the disorder in c other family member For example, a gene for brown eyes is dominant over one for blue eyes which is recessive; a child is born An example of autosomal dominant disease is with a gene for brown eyes and a recessive one for Huntington disease. It is a progressive neurologic blue eyes will have brown eyes. disorder characterized by loss of motor control and intellectual deterioration, symptoms usually manifest A AUTOSOMAL DOMINANT DISEASE at 35-45 y/o. - Although more than 3000 autosomal dominant disorders are known, only a few are commonly seen because the majority of these are not compatible with life after birth. With an autosomal dominant condition, either a person has two unhealthy genes (is homozygous dominant) or is heterozygous, with the gene causing the disease stronger than the corresponding healthy recessive gene for the same trait. - If a person who is heterozygous for an autosomal dominant trait (the usual pattern) mates with a person who is free of the trait, as shown in Figure 1, the chances are even (50%) that a child born to the couple would have the disorder or would be disease and JAZILLE F. BATCH 2026 AUTOSOMAL RECESSIVE C X-LINKED DOMINANT INHERITANCE B INHERITANCE Some genes for disorders are located on, and More than 1500 autosomal recessive disorders have therefore transmitted only by, the female sex been identified. Such diseases do not occur unless chromosome (the X chromosome). There are about two genes for the disease are present (i.e., a 300 known disorders associated this way and their homozygous recessive pattern). Examples include transmission is termed X-linked inheritance. If the cystic fibrosis, albinism, Tay-Sachs disease, affected gene is dominant, only one X chromosome galactosemia, phenylketonuria, Rh Incompatibility) with the trait need be present for symptoms of the disorder to be manifested (Fig. 6). An example of autosomal recessive inheritance is shown in Figure 4. Both parents are disease free of cystic fibrosis, but both are heterozygous in genotype, so they carry a recessive gene for cystic fibrosis. When this genetic pattern occurs, there is a 25% chance that a child born to a a couple will be disease and carrier free (homozygous dominant for the healthy gene); a 50% chance that the child will be, like the Family characteristics seen with this type of b parents, free of disease but carrying the inheritance usually include: unexpressed disease gene (heterozygous); All individuals with the gene are affected (the a 50% chance that the child will be, like the a gene is dominant). c parents, free of disease but carrying the All female children of affected men are unexpressed disease gene (heterozygous); b affected; all male children of affected men are unaffected. c It appears in every generation. All children of homozygous affected women are affected. Fifty percent of the children of d heterozygous affected women are affected (Fig. 7). An example of a disease in this group is Alport’s syndrome, a progressive kidney failure disorder. When family genograms are assessed for the incidence of inherited disease, situations commonly discovered when a recessively inherited disease is present in the family include (Fig.5): Both parents of a child with the disorder are a clinically free of the disorder. The sex of the affected individual is b unimportant in terms of inheritance. The family history for the disorder is negative— that is, no one can identify anyone else who had it (a horizontal transmission pattern). A X-LINKED RECESSIVE c known common ancestor between the parents D sometimes exists. This explains how both male INHERITANCE and female came to possess a like gene for the The majority of X-linked inherited disorders are not disorder dominant, but recessive. When the inheritance of a recessive gene comes from both parents (homozygous recessive) it appears to be incompatible with life. Therefore, females who inherit the affected gene will be heterozygous, and, because a normal gene is also present, the expression of the disease will be blocked. On the other hand, because males have only one X chromosome, the disease will be manifested in any male children who receive the affected gene from their mother. Such a pattern is shown in Figure 8, in which the mother has the affected gene on one of her X chromosomes and the father is disease-free: JAZILLE F. BATCH 2026 a 50% that a male child will manifest the disease more often in girls than boys), but they can occur in 50% that a female child will carry the disease either sex. b gene CHROMOSOMAL ABNORMALITIES F (CYTOGENIC DISORDER) In some instances of genetic disease, the abnormality occurs not because of dominant or recessive gene patterns but through a fault in the number or structure of chromosomes which results in missing or distorted genes. When chromosomes are If the father has the disease and chooses a sexual photographed and displayed, the resulting partner who is free of the disease gene, the chances arrangement is termed a karyotype. are 100% that a daughter will have the sex linked F.1 Nondisjunction Abnormalities recessive gene, but there is no chance that a son will Meiosis is the type of cell division in which have the disease (see Fig. 9). the number of chromosomes in the cell is reduced to the haploid (half) number for reproduction (i.e., 23 rather than 46 chromosomes). All sperm and ova undergo a meiosis cell division early in formation. The cell then divides cleanly, with 23 chromosomes in the first new cell and 23 chromosomes in When X-linked recessive inheritance is present in a the second new cell. family, a family genogram will reveal (Fig. 10): When X-linked recessive inheritance is present in a family, Chromosomal abnormalities occur if the a family genogram will reveal (Fig. 10): division is uneven (nondisjunction). The i Only males in the family will have the disorder. result may be that one new sperm cell or A history of girls dying at birth for unknown ovum has 24 chromosomes and the other ii reasons often exists (females who had the has only 22. If a spermatozoon or ovum affected gene on both X chromosomes). with 24 or 22 chromosomes fuses with a iii Sons of an affected man are unaffected. normal spermatozoon or ovum, the The parents of affected children do not have zygote (sperm and ovum combined) will iv have either 47 or 45 chromosomes, not the disorde the normal 46. The following are the chromosomal abnormalities because of nondisjunction. F.1.1 Down Syndrome / Trisomy 21 syndrome (47XY21+ OR 47XX21+) Trisomy 21, the most frequently occurring chromosomal disorder, occurs in about 1 in 800 pregnancies. In women who are older than 35 years of age, the incidence MULTIFACTORIAL (POLYGENIC) is as 1 in 100 live births. E INHERITANCE Many childhood disorders such as heart disease, The physical features of children with diabetes, pyloric stenosis, cleft lip and palate, neural Down syndrome are: tube disorders, hypertension, and mental illness tend - Broad and flat nose to have a higher-than usual incidence in some - Epicanthal fold (eyelids have extra fold families. They appear to occur from multiple gene of tissue at the inner canthus § Slant combinations possibly combined with environmental palpebral fissure factors. - Brushfield spots (white specks on the iris of the eyes) Diseases caused by multiple factors this way do not - Protruding tongue and small oral cavity follow Mendelian laws because more than a single - Back of the head is flat, neck is short, gene or human lymphocyte antigen (HLA) is and extra pad of fat the base of the involved. Their incidence is so unpredictable. A head causes the skin to be so loose it family history, for instance, may reveal no set pattern. can be lifted easily and so thin it can be Some of these conditions have a predisposition to revealed on a fetal sonogram. occur more frequently in one sex (cleft palate occurs - Low set of ears JAZILLE F. BATCH 2026 - Poor muscle tone or rag doll Children with trisomy 18 syndrome have appearance (toe can touch the nose) three copies of chromosome 18. The - Short and thick fingers, little finger incidence is approximately 0.23 per 1,000 curved inward live births. Their characteristics are: - Wide space between the first and - Cognitively challenged second toes and between first and - Small for gestational age second fingers - Low set of ears - Simian line (single crease in the palm) - Small jaw, small mouth, short neck - Cognitively challenged from an IQ of 50 - Congenital heart defects to 70 or less than 20 - Mishappen fingers and toes (index - Small head size finger deviates or crosses over other - Congenital heart disease: fingers) atrioventricular defect - Rocker-bottom feet (soles of the feet - Stenosis or atresia of the duodenum are often rounded instead of flat) Most - Strabismus and cataract children do not survive beyond infancy. - Altered immune function: prone to upper respiratory tract infection F.1.4 Klinefelter Syndrome (47XXY) - Tends to develop acute lymphocytic Children with Klinefelter syndrome are leukemia males with an extra X chromosome. The - Life span is limited to 50 to 60 years incidence of the syndrome is 1 per 1,000 (aging seems to occur faster than live births. Characteristics of the usual) syndrome may not be noticeable at birth. At puberty, the following are observed: Management of children with trisomy - Small testes and produce ineffective 21 sperm - Early educational and play programs so - Gynecomastia (increased breast size) they can develop to their full capacity. - An increased risk of male breast cancer - Good handwashing since they are prone to infection. F.1.5 Turner syndrome (45XO) - Feed slowly. The enlarged tongue may The child with Turner syndrome (gonadal interfere with swallowing and cause dysgenesis) has only one functional X choking chromosome. The incidence is - Physical examination at birth to enable approximately 1 per 10,000 live births. the detection of the genetic The disorder can be identified during - disorder and the initiation of parental pregnancy because of the extra skin at counseling, support and future the sides of the neck. Their other planning. characteristics are: - Gonodal dysgenesis F.1.2 Patau syndrome / Trisomy 13 - Only one functional ovaries syndrome (47XY13+ OR 47XX13+) - Sterile; no menstruation - Secondary sex characteristics do not In trisomy 13, the child has an extra develop at puberty chromosome 13 and is severely - Edema of the hands and feet cognitively challenged. The incidence of - Coarctation (stricture) of the aorta the syndrome is low, approximately 0.45 - Kidney disorders per 1,000 births. Common findings are: - Hairline at the nape is low set - Midline body disorders such as cleft lip - Webbed and short neck and palate - Congenital heart defect - Heart disorders: ventricular septal - Severely cognitive challenged defects - Abnormal genitalia Management of a child with Turner - Microcephaly Syndrome - Microphthalmos (small eyes) or absent - Human growth hormone - Low-set ears - Estrogen at 13 years old - Supernumerary digits (polydactyly) - To become pregnant IVF with - Most children do not survive beyond surrogate oocyte transfer early childhood F.2 Deletion Abnormalities F.1.3 Edwards syndrome / Trisomy 18 are a form of chromosome disorder in syndrome (47XY18+ OR 47XX18+ which part of a chromosome breaks during cell division, causing the affected person to have the normal number of JAZILLE F. BATCH 2026 chromosomes plus or minus an extra The parent’s appearance and functioning portion of a chromosome, such as 45.75 are normal because the total chromosomes or 47.5 chromosome count is a normal 46. He or she is termed a balanced translocation F.2.1 Cri-du-chat syndrome (46XY5P-) carrier. In cri-du-chat syndrome (46XY5q_), one portion of chromosome 5 is missing. If, during meiosis, this abnormal - Abnormal cry (sound of a cat than chromosome 14 (carrying the extra 21 human) chromosome) and a normal chromosome - Small head 21 from the other parent are both - Wide-set eyes included in one sperm or ovum, the - Downward slant palpebral fissure of the resulting child will have a total of 47 eye chromosomes because of the extra - Recessed mandible number 21. Such a child is said to have - Severely cognitively challenge an unbalanced translocation syndrome. The phenotype (appearance) of the child will be indistinguishable from that of a F.2.2 Fragile X Syndrome (46XY23Q-) child with the form of Down syndrome is the most common cause of cognitive that occurs from simple nondisjunction. challenge in males. It is an X-linked F.4 Mosaicism disorder in which on long arm of an X is an abnormal condition that is present chromosome is defective, which results in when the nondisjunction disorder occurs inadequate protein synaptic responses. after fertilization of the ovum, as the The incidence of the syndrome is about 1 structure begins mitotic division (in simple in 4,000 males. The following are the nondisjunction, uneven cell division characteristics of a boy with fragile X occurs during meiosis. syndrome: If this occurs, different cells in the body - Hyperactivity, aggression, or autism will have different chromosome counts. - Reduced intellectual functioning, with The extent of the disorder depends on the marked deficits in speech and arithmetic proportion of tissue with normal - Large head, long face with high forehead chromosome structure to tissue with - Prominent lower jaw abnormal chromosome constitution. - Large protruding ears - Obesity Children with Down syndrome who have - Hyper extensive joints near normal intelligence may have this - Cardiac disorders type of pattern. - After puberty: enlarged testicles; fertile and can reproduce The occurrence of such a phenomenon at - Carrier females may show evidence of this stage of development suggests that the physical and cognitive characteristics a teratogenic (harmful to the fetus) condition, such as x-ray or drug Management exposure, existed at that point to disturb Stimulants, atypical antispyschotics, normal cell division. This genetic pattern serotonin reuptake inhibitors may improve in a female with Down syndrome caused symptoms of poor concentrations and by mosaicism would be abbreviated as impulsivity 46XX/47XX21_ to show that some cells contain 46 and some 47 chromosomes. F.3 Translocation Abnormalities are perplexing situations in which a child F.5 Isochromosomes gains an additional chromosome through If a chromosome accidentally divides not another route. A form of Down syndrome by a vertical separation but by a occurs as an example of this. horizontal one, a new chromosome with mismatched long and short arms can In this instance, one parent of the child result. This is an isochromosome. It has has the correct number of chromosomes much the same effect as a translocation (46), but chromosome 21 is misplaced; it abnormality when an entire extra is abnormally attached to another chromosome exists. chromosome, such as chromosome 14 or 15. Some instances of Turner syndrome (45XO) may occur because of isochromosome formation. JAZILLE F. BATCH 2026 GENETIC COUNSELLING AND TESTING Any individual who has an inborn error of It is advantageous for an individual concerned with metabolism or chromosomal disorder. Any the possibility of transmitting a disease to his or her person with a disease should know the children to ask for genetic counseling at a inheritance pattern of the disease and, like preconception health visit for advice on the those who are balanced translocation carriers, inheritance of disease because counseling can serve should be aware if prenatal diagnosis is to: possible for his or her particular disorder. Provide concrete, accurate information about 1 the process of inheritance and inherited A consanguineous (closely related) couple. disorders The more closely related are two people, the Reassure people who are concerned that their more genes they have in common, so the more 2 child may inherit a particular disorder that the likely it is that a recessively inherited disease disorder will not occur will be expressed. A brother and sister, for Allow people who are affected by inherited example, have about 50% of their genes in 3 disorders to make informed choices about common; first cousins have about 12% of their future reproduction genes in common. Allow people to pursue potential interventions 4 Any woman older than 35 years and any that may exist such fetal surgery. Allow families to begin preparation for a child man older than 55 years. This is directly with special needs Couples who are most apt related to the association between advanced to benefit from a referral for genetic testing or parental age and the occurrence of Down counseling include: syndrome. A couple who has a child with a congenital Couples of ethnic backgrounds in which disorder or an inborn error of metabolism. specific illnesses are known to occur. Many congenital disorders occur because of Mediterranean people, for example, have a teratogenic invasion during pregnancy that has high incidence of thalassemia, a blood gone unrecognized. Learning that the disorder; those with a Chinese ancestry have a abnormality occurred by chance rather than high incidence of glucose-6- phosphate inheritance is important, because the couple dehydrogenase (G6PD) deficiency, a blood will not have to spend the remainder of their disorder where destruction of red cells can childbearing years in fear that another child occur may be born with the disorder (although a chance circumstance could occur again). If a NURSING PROCESS FOR GENETIC definite teratogenic agent, such as a drug a ASSESSMENT AND COUNSELING woman took during pregnancy, can be identified, the couple can be advised about ASESSMENT OF GENETIC DISORDER preventing this occurrence in a future Genetic assessment begins with careful study of the pregnancy. pattern of inheritance in a family. A history, physical 5 examination of family members, and laboratory A couple whose close relatives have a child analysis, such as karyotyping or DNA analysis, are with a genetic disorder such as a performed to define the extent of the problem and the chromosomal disorder or an inborn error of chance of inheritance. metabolism. It is difficult to predict the (1) - Diseases in family members expected occurrence of many “familial” or for a minimum of three multifactorial disorders. In these instances, History generations (include half counseling should be aimed at educating the brother and sisters or anyone couple about the disorder, treatment available, related in any way as family) and the prognosis or outcome of the disorder. - Document whether the Based on this information, the couple can parents are consanguineous make an informed reproductive choice about or related to each other children. - Include family’s ethnic back ground Any individual who is a known carrier of - Obtain as much as information chromosomal disorder. Understanding of his by letting the couple describe or her own chromosome structure and the the appearance or process by which future children could be - activities of affected individual affected can help such an individual make an or asking permission to obtain informed choice about reproduction or can alert health records him or her to the importance of fetal karyotyping during any future pregnancy JAZILLE F. BATCH 2026 - Obtain an extensive prenatal During first trimester, women are history of any affected person offered a routine sonogram whether screening (a nuchal translucency - environmental conditions scan) and an analysis of could account for the maternal serum levels of alpha condition. fetoprotein (MSAFP), pregnancy - Draw a family genogram to associated plasma protein A identify the possibility of a (PAPP-A), and free beta hCG to chromosomal disorder evaluate for chromosomal - occurring in a particular disorders in the fetus. couple’s children and identify Additionally, women over the age other family member who of 35 years may be offered a might benefit from genetic more accurate noninvasive blood counseling. test, circulating cell-free DNA (2) Because genetic disorders often (cfDNA) testing, to screen for Physical occur in varying degrees of chromosomal disorders. The expression, a careful physical chorionic villi sampling and assessment assessment of any family amniocentesis are diagnostic member with a disorder, that tests that assess the karyotype child’s siblings, and the couple when fetal chromosomes are seeking counseling is needed. photographed and displayed, During inspection, pay particular which can provide a definite attention to certain body areas, answer about the presences or such as: absences of disorders. - the space between the eyes - the height, Deciding to terminate a - contour, and shape of ears pregnancy based on a laboratory - the number of fingers and finding is rarely easy. If a couple toes, and the presence of decides to terminate pregnancy, webbing. they need support for their - Dermatoglyphics (the study of decision to end the pregnancy. If surface markings of the skin) they decide not to terminate the can also be helpful. pregnancy, they may need - abnormal fingerprints or support during the remainder of palmar creases the pregnancy and in the days - abnormal hair whorls or following birth. coloring of hair can also be present. 3.1 Karyotyping Careful inspection of newborns is For karyotyping, a sample of peripheral often sufficient to identify a child venous blood or a scraping of cells from with a potential chromosomal the buccal membrane is taken. Cells are disorder. Infants with multiple allowed to grow until they reach congenital anomalies, those born metaphase, the most easily observed at less than 35 weeks’ gestation, phase. Cells are then stained, placed and those whose parents have under a microscope, and photographed. had other children with Chromosomes are identified according to chromosomal disorders need size, shape, and stain; cut from the extremely close assessment. photograph, and arranged. Any additional, (3) Many diagnostic tests are lacking, or abnormal chromosomes can be Screening available to provide important visualized by this method. and clues about possible disorders. Before pregnancy, A newer method of staining, FISH, allows diagnostic DNA analysis or karyotyping of karyotyping to be done immediately, rather testing both parents and an already than waiting for the cells to reach affected child provides a picture metaphase. This makes it possible for a of the family’s genetic pattern report to be obtained in only 1 day. Fetal and can be used for prediction in skin cells can be obtained by future children. Once a woman is amniocentesis or CVS. A few fetal cells pregnant, several other tests may circulate in the maternal bloodstream, most be performed to help in the noticeably trophoblasts, lymphocytes, and prenatal diagnosis of genetic granulocytes. disorder (Table 3 and Table 4). JAZILLE F. BATCH 2026 They are present but few in number during the first and second trimesters but plentiful during the third trimester. Such cells can be cultured and used for genetic testing for such disorders as the trisomies. 3.2 Chorionic Villi Sampling CVS is a diagnostic technique that involves the retrieval and analysis of chorionic villi from the growing placenta for chromosome or DNA analysis. The test is highly accurate and yields no more false-positive results than does amniocentesis. Although this procedure may be done as early as 3.3 Amniocentesis. week 5 of pregnancy, it is more commonly is the withdrawal of amniotic fluid through done at 8 to 10 weeks. With this technique, the abdominal wall for analysis at the 14th the chorion cells are located by ultrasound. to 16th week of pregnancy. Because A thin catheter is then inserted vaginally, or amniotic fluid has reached about 200 mL at a biopsy needle is inserted abdominally or this point, enough fluid can be withdrawn intravaginally, and a number of chorionic for karyotyping of skin cells found in the cells are removed for analysis (Fig. 11). fluid as well as an analysis of AFP or CVS carries a small risk (less than 1%) of acetylcholinesterase. If no causing excessive bleeding, leading to acetylcholinesterase, a breakdown product pregnancy loss. There have been some of blood, is found in the specimen, it instances of children being born with confirms that an elevated AFP level is not missing limbs after the procedure (limb a false-positive reading caused by blood in reduction syndrome). This has occurred the fluid. For the procedure, a pocket of with a high enough frequency that women amniotic fluid is located by ultrasound. need to be well informed of these risks Then a needle is inserted beforehand. After CVS, instruct a woman transabdominally, and about 20 mL of fluid to report chills or fever suggestive of is aspirated. Skin cells in the fluid are infection or symptoms of threatened karyotyped for chromosomal number and miscarriage (uterine contractions or structure. The level of AFP is analyzed. vaginal bleeding). Women with an Rh- Some disorders, such as Tay-Sachs negative blood type need Rh immune disease, can be identified by the lack of a globulin administration after the procedure specific enzyme, such as hexosaminidase to guard against isoimmunization in the A, in amniotic fluid. Amniocentesis has the fetus. The cells removed in CVS are advantage over CVS of carrying only a karyotyped or submitted for DNA analysis 0.5% risk of spontaneous miscarriage. to reveal whether the fetus has a genetic Unfortunately, it usually is not done until disorder. Because chorionic villi cells are the 14th to 16th week of pregnancy. This rapidly dividing, results are available may prove to be a difficult time because, by quickly, perhaps as soon as the next day. this date, a woman is beginning to accept If a twin or multiple pregnancy is present, her pregnancy and bond with the fetus. In with two or more separate placentas, cells addition, termination of pregnancy during should be removed separately from each the second trimester is more difficult than placenta. Because fraternal twins are during a first trimester. Support women derived from separate ova, one twin could while they wait for test results and to make have a chromosomal abnormality while the a decision about the pregnancy. Women other does not. Not all inherited diseases with an Rh-negative blood type need Rh can be detected by CVS. Be certain that immune globulin administration after the parents understand that only those procedure to protect against disorders involving abnormal isoimmunization in the fetus. All women chromosomes or nondisjunction, and those need to be observed for about 30 minutes whose specific gene location is known, can after the procedure to be certain that labor be identified by CVS. The test is not apt to contractions are not beginning and that the reveal the extent of spinal cord fetal heart rate remains within normal limits abnormalities, for example. JAZILLE F. BATCH 2026 3.4 Levels of four substances in pregnant women's blood (Quadruple screening) during 15-18 weeks of pregnancy (Table 5) 1. Alpha-fetoprotein (AFP), a protein made by the developing baby 2. Human chorionic gonadotropin (HCG), by the placenta 3. Estriol, a hormone made by the placenta and the baby's liver 4. Inhibin A, by the placenta NURSING DIAGNOSIS Typical nursing diagnoses related to the area of genetic disorders include: 1. Decisional conflict related to testing for an untreatable genetic disorder 2. Fear related to outcome of genetic screening tests 3. Situational low self-esteem related to identified chromosomal abnormality 4. Deficient knowledge related to inheritance pattern of the family’s inherited disorder 5. Health-seeking behaviors related to potential for genetic transmission of disease 6. Altered sexuality pattern related to fear of conceiving a child with a genetic disorder OUTCOME IDENTIFICATION AND PLANNING Outcome identification and planning for families undergoing genetic assessment differ according to the types of assessments performed and the results obtained. This may include determining what JAZILLE F. BATCH 2026 information the couple needs to know before testing can proceed or helping couples arrange for further assessment measures. Be certain that goals are realistic and consistent with the individual’s or couple’s lifestyle (not all people want to be totally informed about family illnesses). IMPLEMENTATION Parental reactions to the knowledge that their child has a possible genetic disorder or to the birth of a child with a genetically inherited disorder usually involves a grief reaction, similar to that experienced by parents whose child has died at birth (their “perfect” child is gone). Both parents may pass through stages of: 1. Shock and denial (“This cannot be true”), 2. Anger (“It’s not fair that this happened to us”), 3. Bargaining (“If only this would go away”) 4. Acceptance (“It has happened to us and it is all right”). OUTCOME EVALUATION Examples of expected outcomes for a family with a known genetic disorder might be: 1. Couple states they feel capable of coping no matter what the outcome of genetic testing. 2. Client accurately states the chances of a genetic disorder occurring in her next child. 3. Couple states they have resolved their feelings of low self-esteem related to birth of a child with a genetic disorder. A couple’s decisions about genetic testing and childbearing can change over time. For example, a decision made at age 25 not to have children because of a potential genetic disorder may be difficult to maintain at age 30, as the couple sees many of their friends with growing families. Be certain that such couples have the telephone number of a genetic counselor. Urge them to call periodically for news of recent advances in genetic screening techniques or disease treatments so they can remain current and well informed for future planning. JAZILLE F. BATCH 2026

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