Maternal And Child Health Nursing - The Growing Fetus PDF

MATERNAL AND CHILD FERTILIZATION: THE BEGINNING OF PREGNANCY HEALTH NURSING - THE GROWING FETUS I. Fertilization:The Beginning of Pregnancy STAGES OF FETA...

MATERNAL AND CHILD FERTILIZATION: THE BEGINNING OF PREGNANCY HEALTH NURSING - THE GROWING FETUS I. Fertilization:The Beginning of Pregnancy STAGES OF FETAL DEVELOPMENT Fertilization (conception, impregnation Terms used to denote fetal growth: or fecundation) -the union of an ovum and a spermatozoon in the outer third of Ovum - From ovulation to fertilization a fallopian tube, the ampullary portion. General considerations: - only one ovum reaches maturity each month. - once released, fertilization must occur fairly quickly - ovum is only capable of Zygote - From fertilization to fertilization for only 24 hours (48 implantation hours at the most) - After that, it atrophies and becomes nonfunctional. - The total critical time span then, for fertilization to be successful is about 72 hours (48 hrs before ovulation plus 24 hrs Embryo - From implantation to 5-8 wks afterward) Fetus - From 5-8 wks until term Conceptus - Developing embryo or fetus and placental structures throughout pregnancy Ovum - Sperms, once deposited in the - Zona Pellucida – ring of vagina, will generally reach the mucopolysaccharide fluid cervix within 90 seconds. surrounding an ovum. - reaches outer fallopian tube - Corona radiata: circle of cells within 5 minutes - Zona Pellucida and Corona (this is why douching is not an effective Radiata: increase the bulk of the contraceptive) ovum and serve as protective - Spermatozoa move by means of buffers against injury their flagella (tails) and uterine contractions through the cervix and the body of the uterus and into the fallopian tubes, toward the waiting ovum. Capacitation - Capacitation – the final process that sperm must undergo to be ready for fertilization. - consists of changes in the - Ovum is propelled into a nearby plasma membrane of the sperm fallopian tube by currents initiated head , which reveal the by the fimbriae-the fine hairlike sperm-binding receptor site. structures that line the openings - all of the spermatozoa that of the fallopian tube. achieve capacitation reach the - A combination of peristaltic action ovum and cluster around the of the tube and movements of the protective layer of corona cells. tube cilia help propel the ovum along the length of the tube. Hyaluronidase - Hyaluronidase( a proteolytic Sperm enzyme) – released by the - normal amount of semen per spermatozoa and acts to dissolve ejaculation – 2.5 ml of fluid the layer of cells protecting the - Number of sperms/cc/ml – ovum. 50-200 million or average of 400 million sperm per ejaculation. Zygote - Sperms are capable of fertilizing - the resulting structure when even for 3-4 days after chromosomal material of the ejaculation. ovum and spermatozoon fuse - Normal life span of sperms – 7 immediately after the penetration days of the ovum.  - Zygote – 46 chromosomes - Morula continues to multiply as it chromosomes – DNA-containing floats freely in the uterine cavity structure of cellular organism for 3 or 4 more days — large autosomes – chromosomes that do not cells tend to collect at the the determine the sex periphery of the ball, leaving a Sperm (22 autosomes and 1 X or 1 Y fluid space surrounding the inner sex chromosomes) cell mass — now known as Ova (22 autosomes and 1 X sex blastocyst (the structure that chromosome) attaches to the uterine - Only fathers determine the sex of endometrium). their children. - The cells in the outer ring are Ex. The union of Y-carrying sperm and trophoblast cells. They are part a mature ovum results in a baby boy of the structure that will later form (XY); If xx – results in a baby girl the placenta and membranes. - The inner cell mass Fertilization is never a certain (embryoblast cells) is the portion occurrence of the structure that will form the - because it depends on at least embryo. three separate factors: 1. equal maturation of both sperm and ovum, 2. the ability of the sperm to reach the ovum 3. The ability of the sperm to penetrate the zona pellucida and cell membrane and achieve fertilization. Implantation Fertilization is complete – over 3-4 days – zygote migrates toward the body of uterus — mitotic cell division or cleavage begins (blastomere) — 1st cleavage occurs at about 24 hrs — cleavage divisions continue to occur at a rate of one about every 22 hrs — consists of 16 to 50 cells by the time the zygote reaches the body of the uterus — now known as morula.  - Trophoblast – are cells in the The three layers together are known as outer ring. Part of the structure the embryonic plate. that will later form the placenta and membranes. - They produce proteolytic enzymes that dissolve any tissue they touch. - The action allows the blastocyst to burrow deeply into the endometrium and receive basic nourishment of glycogen and mucoprotein from the endometrial gland. - Implantation, or contact between the growing structure and the uterine endometrium, occurs approximately 8 to 10 days after fertilization. - After the 3rd or 4th day of free floating (about 8 days after ovulation) –the blastocyst sheds the last residues of the corona and zona pellucida. THE INNER CELL MASS - The structure brushes against the - While trophoblast is developing rich uterine endometrium, a into the placenta, which will process termed apposition. nourish the fetus, the inner cell - It attaches to the surface of the mass is forming the fetus itself. endometrium (adhesion) and settles down into its soft folds Three layers of the inner cell mass: (invasion). 1. The ectoderm – forms the skin and nervous system. 2. The mesoderm – forms bones and muscles and also the heart and blood vessels, including those in the placenta. 3. The endoderm – forms mucous membranes and glands. (INVASION) Abnormal Implantation - This drawing (below) illustrates a phenomenon known as implantation bleeding. Maternal blood fills the cavities in the trophoblast. - The trophoblast surrounds the whole embryo and just before it is completely covered some of blood in the superficial cavities might leak into the uterine cavity and escape via the vagina. - This implantation bleeding occurs exactly at the time of the expected menstruation. It therefore can cause uncertainty - Implantation point is usually high about the duration of pregnancy. in the uterus, on the posterior Implantation bleeding seldom surface. occurs. Once implanted, the zygote becomes The Decidua ( latin: falling off ) an embryo - the name given to the endometrium during pregnancy. Three separate areas: Decidua Basalis – lies directly under the embryo. Decidua capsularis – the portion of the endometrium that stretches or encapsulates the surface of the trophoblast. Decidua vera – the remaining portion of the uterine lining. EMBRYONIC AND FETAL STRUCTURES Placenta - The placenta, which will serve as the fetal lungs, kidneys, and digestive tract in utero, begins growth in early pregnancy in coordination with embryo growth. Decidua - After fertilization, the corpus luteum continues to function - as embryo continues to grow, it because of the influence of hCG. pushes the decidua capsularis - Uterine endometrium continues before it like a blanket. to grow in thickness and - Eventually, enlargement brings vascularity. the structure into contact with the - Endometrium is now termed opposite uterine wall. decidua and will be discarded - At birth, the entire inner surface only after birth. of the uterus is stripped away, leaving the organ highly susceptible to hemorrhage and infection. Chorionic Villi - initially the ovum appears to be covered with fine, downy hair surrounding the ovum.  - These proliferate and branch from about 3 weeks after fertilization, forming the chorionic villi. - At term, almost 200 villi will have formed. - It is most profuse in the area where the blood supply is the richest – that is, the basal decidua. 2. The cytotrophoblast - The villi erode the walls of - The hormone is responsible for maternal blood vessels as they informing the corpus luteum that penetrate the decidua, opening a pregnancy has begun. The them up to form a lake of corpus luteum continues to maternal blood in which they produce estrogen and float. A few villi are more deeply progesterone. Menstruation then attached to the decidua and are is suppressed. called anchoring villi. - protect the growing embryo and fetus from certain infectious organisms such as spirochete or syphilis. - Cytotrophoblast or Langhans layer –is present as early as 12 days gestation. - disappears between the 20th and 24th week. TWO OUTER COVERING : - the reason why syphilis is 1. The syncytiotrophoblast considered to have a high - capable of breaking down tissue potential for fetal damage late in as in the process of embedding. pregnancy. It erodes the walls of the blood vessels of the decidua, making nutrients in the maternal blood THE PLACENTA ( latin for pancake ) accessible to the developing - arises out of trophoblast tissue organism. - It serves as the fetal lungs, - Produces hCG, kidneys, and gastrointestinal tract somatomammotropin, estrogen and as a separate endocrine and progesterone organ throughout pregnancy. - Its growth parallels that of the fetus, growing from a few  identifiable cells at the beginning Note: of pregnancy to an organ 15 to - There is no direct exchange of 20 cm in diameter and 2 to 3 cm blood between the embryo and in depth at term. the mother during the pregnancy. - The exchange is carried out only by selective osmosis through the chorionic villi. - Minute breaks allow occasional fetal cells to cross as chorionic villi is only one cell thick. - Placental osmosis is so effective that all but a few substances are able to cross from the mother into the fetus. - It is important that a woman take no nonessential drugs ( including alcohol and nicotine) during pregnancy. Mechanisms by Which Nutrients Cross the Placenta 1. Diffusion - When there is a greater concentration of a Placental Circulation substance on one side of a - 12th day of pregnancy – maternal semipermeable membrane than blood begins to collect in the on the other, substances of intervillous spaces of the uterine correct molecular weight cross endometrium surrounding the the membrane from the area of chorionic villi higher concentration to the area - 3rd week : oxygen and other of lower concentration. Oxygen, nutrients, such as glucose, amino carbon dioxide, sodium, and acids, fatty acids, minerals, chloride cross the placenta by vitamins, and water diffuse from this method. the maternal blood through the cell layers of the chorionic villi to 2. Facilitated Diffusion - To ensure the villi capillaries that the fetus receives enough - From there: nutrients are concentrations of necessary transported back to the growth substances, some developing embryo. substances cross the placenta  more rapidly or more easily - intervillous spaces grow larger without the expenditure of energy. and larger, becoming separated A carrier moves the substance by a series of partitions or septa. into and through the membrane. - in a mature placenta, there are as Glucose is an example of a many as 30 separate segments, substance that crosses by this called cotyledons. process. - These compartments are what make the maternal side of the 3. Active Transport - This process placenta look rough and uneven. requires energy and action of an enzyme to facilitate transport. Essential amino acids and water-soluble vitamins cross the placenta against the pressure gradient or from an area of lower molecular concentration to an area of greater molecular concentration. 4. Pinocytosis - Absorption by the Duncan/Shultz presentation cellular membrane of microdroplets of plasma and dissolved substances. Gamma globulin, lipoproteins, phospholipids, and other molecular structures that are too large for diffusion and that cannot participate in active transport cross in this manner. Viruses that infect the fetus can also cross in this manner. Blood supply - About 100 maternal uterine Cotyledons arteries supply the mature - as the number of chorionic villi placenta. increases with pregnancy, the villi - to provide enough blood for form an increasingly complex exchange, the rate of communication network with the uteroplacental blood flow in maternal blood. pregnancy increases from 50ml/min at 10 weeks to 500 to 600 ml/min at term.  - no additional maternal arteries Role of hCG appear after the first 3 months of pregnancy; instead, to a. act as a fail-safe measure to ensure accommodate the increased that the corpus luteum of the ovary blood flow, the arteries increase continues to produce progesterone and in size. estrogen. - Systematically, the mother’s heart - if corpus luteum should fail and rate, total cardiac output, and the level of progesterone fall, this would blood volume increase to supply cause endometrial sloughing, with loss the placenta. of pregnancy followed by a rise of pituitary gonadotropins to induce menstrual cycle. b. Supressess the maternal immunologic response so that placental tissue is not rejected c. If the fetus is male, it exerts an effect on the fetal testes to begin testosterone production, because hCG structure is Endocrine Function in Pregnancy similar to that of LH. 1. Human Chorionic Gonadotropin 2. Estrogen - first hormone produced - produced as a second product of - can be found in maternal blood and the syncytial cells of the placenta. urine as early as the first missed - contributes to the mother’s menstrual period ( shortly after mammary gland in preparation for implantation has occurred) lactation and stimulates uterine growth - a false-negative result from a to accommodate the developing fetus. pregnancy test may be reported before - “ hormone of women” or after this period. 3. Progesterone - mother’s serum will be completely - “ hormone of mothers” negative for hCG within 1 to 2 weeks - necessary in pregnancy to after birth. maintain the endometrial lining of the - testing for hCG after birth can be uterus. used as proof that all of the placental - present in serum as early as the tissue has been delivered. 4th week of pregnancy. - rises progressively during the remainder of pregnancy  - helps prevent premature labor as it that surface its typically shiny reduces the contractility of the uterine appearance. musculature during pregnancy. - no nerve supply - spontaneously rupture at term or 4. Human Placental lactogen ( Human artificially ruptured Chorionic Somatomammotropin) - produces the amniotic fluid - a hormone with both - also produces a phospholipid that growth-promoting and lactogenic initiates the formation of prostaglandins, (milk-producing) properties. which can cause uterine contractions - produced by the placenta as early and may be the trigger that initiates as the 6th week of pregnancy. labor. - be assayed in both maternal serum and urine. Amnion / Chorion - promotes mammary gland growth in preparation for lactation in the mother. - also serves the important role of regulating maternal glucose, protein, and fat levels so that adequate amounts of these nutrients are always available to the fetus. The Amniotic Membranes Formation of Chorion - the chorionic villi on the medial surface of the trophoblast gradually thin, The Amniotic Fluid leaving the medial surface of the structure smooth (smooth chorion ) - is constantly being newly formed by - smooth chorion eventually the amniotic membrane, so it never becomes the chorionic membrane, the becomes stagnant. outermost fetal membrane. - slightly alkaline, with a pH of about - once it becomes smooth, it offers 7.2 support to the sac that contains the - absorption : amniotic fluid. a. direct contact with the fetal surface of the placenta Formation of Amnion b. fetus continually swallows the - second membrane lining the fluid, the major method of absorption chorionic membrane c. in the fetal intestine, it is - forms beneath the chorion absorbed into the fetal bloodstream – - at birth, they can be seen covering umbilical arteries – to placenta – the fetal surface of the placenta, giving exchanged across the placenta.  - protects fetus from changes of temperature - probably aids in muscular development, because it allows the fetus the freedom to move. - protects the umbilical cord from pressure, protecting the fetal oxygen supply. Amount at term – 800-1,200 mL Hydramnios – excessive amniotic fluid - more than 2,000 mL - commonly due to : esophageal atresia or anencephaly - also tends to occur in women with diabetes The Umbilical Cord Oligohydramnios – reduction in the amount of amniotic fluid Umbilical Cord / Funis - due to the disturbance in i. Description the fetal kidney function - is formed from the fetal membranes - less than 300 mL ( amnion and chorion ) - provides a circulatory pathway that connects the embryo to the chorionic villi of the placenta. ii. Function - transport oxygen and nutrients to the fetus from the placenta and to return waste products from the fetus to the placenta. Function of amniotic fluid: -serves as an important protective mechanism for fetus. - shield against pressure or a blow to the mother’s abdomen. iii. Characteristics - in about 20% of all births, a loose loop - about 53 cm (21 in) in length at of cord is found around the fetal neck term (nuchal cord). - about 2 cm ( ¾ in ) thick - The walls of umbilical cord arteries - The bulk of the cord is gelatinous are lined with smooth muscle. mucopolysaccharide called “ Wharton’s Constriction of these muscles after birth jelly “, it gives the cord body and contributes to hemostasis and helps prevents pressure on the vein and prevent hemorrhage. arteries that pass through it. - it does not contain nerve supply, - outer surface is covered with thus it can be cut at birth without amniotic membrane. discomfort to either the child or mother. - umbilical cord contains : 1 vein ( carrying blood from the placental villi to the fetus), and 2 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. - blood can be withdrawn from the umbilical vein or transfused into the vein ORIGIN AND DEVELOPMENT OF during intrauterine life for fetal ORGAN SYSTEMS assessment or treatment. a. Stem Cells - rate of blood flow: 350 mL/min at term b. Zygote Growth and rapid c. Primary Germ Layers - cord is unlikely to twist or knot due to d. Cardiovascular System its rapidity e. Fetal Circulation f. Fetal Hemoglobin g. Respiratory System h. Nervous System i. Endocrine System j. Digestive System k. Musculoskeletal System l. Reproductive System m. Urinary System n. Integumentary system o. Immune system  A. Stem Cells these have the potential to be able to 1. Totipotent stem cells ( zygote cells ) supply any type of body cell needed by - occurs during the first 4 days of life the adult donor. - so undifferentiated that they have the potential to form a complete human B. Zygote Growth - being. Development proceeds in a 2. Pluripotent stem cells cephalocaudal direction. - in another 4 days, the structure implants and becomes an embryo- C. Primary Germ Layer begin to show differentiation and are no 1. Ectoderm : a distinctive layer of cells, longer capable of becoming any body arises from the amniotic cavity which is cell – slated now to become specific the largest. body cells, such as nerve, brain, or skin 2. Entoderm : arises from the yolk sac , cells. a smaller cavity 3. Multipotent stem cells - yolk sac appears to supply - specifically that they have set a nourishment only after implantation. sure course toward what body organ - After that, its main purpose is to they will create. provide a source of red blood cells until the embryo’s hematopoietic system is mature enough to perform this function. - it then atrophies and remains only as white streak discernible in the cord at birth. 3. Mesoderm – 3rd layer Implications of the Primary Germ layers: - each of these germ layers, primary tissue develops into specific body systems ( see table) 2 types of Cloning: - coexisting congenital defects found in newborns usually arise from the same 1. Reproductive cloning layer. - the nucleus is removed from an ex. Esophageal and tracheal fistula ( oocyte and the nucleus of an adult cell entoderm ) is transferred into the oocyte, the Heart and kidney defects ( embryo has the potential to grow into an mesoderm) infant that is identical to the adult donor. Bladder and urethral defects ( 2. Therapeutic cloning entoderm ) - pluripotent stem cells are removed Note: and allowed to grow in the laboratory,  - Rubella infection is serious in - 10th to 12th week : heartbeat pregnancy as it can infect all three germ maybe heard thru a Doppler layers, thereby causing congenital instrument anomalies - 11th week : ECG - Screening procedures are ordered for - After 28th week : 5 beats/min thru newborns with congenital a fetal heart rate rhythm strip. malformations. e.g radiographic exam of the kidney with a child born with heart defects. - At 8 week’s gestation ( the end of embryonic period), all organ systems are complete. D1. Fetal Circulation 3rd week of intrauterine life, fetal blood - Organogenesis – the growing begins to exchange nutrients with structure is most vulnerable to maternal circulation across the chorionic invasion by teratogens villi. Fetus derives oxygen and excretes D. Cardiovascular System carbon dioxide from the placenta. - One of the first systems to The blood flow is to supply the cells of become functional in intrauterine the lungs. life. Specialized structures present in the - Forms as early as the 16th day of fetus shunt blood flow to supply the life and beats as early as the 24th most important organs of the body: the day. brain, the heart, and kidneys. - 6th or 7th week: septum that Blood from the placenta is highly divides the heart into chambers is oxygenated. developed. Blood enters the fetus through the umbilical vein (called a vein even though it carries oxygenated blood, bec the back through the umbilical cord to direction of the blood is toward the fetal the placental villi, where new heart). oxygen exchange takes place. - 80% - blood oxygen saturation level of the fetus - Rapid fetal heart rate ( 120 to 160/min ) is necessary to supply oxygen to cells. D2. Fetal Hemoglobin - Compose of two alpha and two gamma chains ( adult: two alpha - This vein carries the blood to the and two beta chains) inferior vena cava through an - More concentrated accessory structure, the ductus - Has greater oxygen affinity venosus, which allows - 17.1g/100mL hg level (adult : oxygenated blood to be supplied 11g/100 mL) directly to the fetal liver. - 53% hct level ( adult : 45% ) - Oxygenated blood then empties into the inferior vena cava and is E. Respiratory System carried to the right side of the - 3rd week: respiratory and heart. digestive tracts exist as a single - The blood then enters the right tube. atrium, into the left atrium through - Initially it is a solid structure, an opening in the atrial septum, canalizes then by the end of 4th called foramen ovale. week, a septum begins to divide - From the left atrium, it follows the the esophagus and trachea- at course of normal circulation into the same time, lung buds appear the left ventricle and into the on the trachea. aorta. Note: - Ductus arteriosus- shunts away - Diaphragmatic hernia or intestine from the lungs a small amount of still present in the chest occurs if blood that returns to the heart the diaphragm fails to close directly into the descending aorta. completely by the end of 7th - Most of the blood flow from the week. descending aorta is transported by the umbilical arteries ( called Important respiratory developmental arteries, even though they are milestones: now transporting deoxygenated - Alveoli and capillaries begin to blood, bec they are carrying form between the 24th and 28th blood away from the fetal heart) weeks.  - 3 mos : spontaneous respiratory - The fetal pancreas produces the practice moves begin insulin needed by the fetus ( - Specific lung fluid with a low insulin does not cross the surface tension and low viscosity placenta from the mother to the forms in alveoli to aid in fetus ) expansion of the alveoli at birth; it - The thyroid and parathyroid is rapidly absorbed after birth. glands play vital roles in - Surfactant, formed at about the metabolic function and calcium 24th week. balance. F. Nervous system H. Digestive System - Begins to develop extremely - 4th week ; separates from the early in pregnancy, during the 3rd respiratory tract and 4th weeks of life. - 16th week : meconium forms Milestones : - GIT tract is sterile before birth, - 3rd week : neural plate ( vitamin K level is low thickened portion of the - 32 weeks or 1,500 g : sucking ectoderm) is apparent. and swallowing reflexes matures - the top portion differentiates into - 36 weeks: ability of the GIT to the neural tube, which forms into secrete enzymes essential to the brain and spinal cord. carbohydrate and protein - 8th week : brain waves can be digestion is mature. detected by EEG - All parts of the brain form in Liver is active throughout gestation utero. - functions as filter between the - The eye and inner ear develop as incoming blood and fetal circulation projections of the original neural - and a deposit site for fetal store such tube. as iron and glycogen - 24 weeks : ear is capable of responding to sound; eyes exhibit I. Musculoskeletal system a pupillary reaction, indicating - 11th week : fetus can be seen that sight is present. moving through ultrasound Note: - 20 weeks : quickening can be felt - Meningocele ( spinal cord disorder ) – by the mother may occur because of lack of folic acid. J. Reproductive System G. Endocrine System - Child’s sex is determined at the - Fetal adrenal glands supply a moment of conception precursor for estrogen synthesis - 8th week : can be ascertained by the placenta. through chromosomal analysis  - 6th week: gonads ( testes and kidneys are not secreting ovaries ) form adequate urine. - Testes first form in the abdominal cavity L. Integumentary System - 34th to 38th week : testes - The skin of a fetus appears thin descend into the scrotal sac and almost translucent until Note: subcutaneous fat begins to be * If testes is formed : testosterone is deposited at about 36 weeks. secreted influencing the sexually neutral - Skin is covered by : genital duct to form other male organs ( 1. lanugo - soft downy hairs maturity of the wolffian, or mesonephric, 2. vernix caseosa - a cream duct ). cheese-like substance, important * if no testosterone : female organs will for lubrication and for keeping the form ( maturation of the müllerian, or skin from macerating in utero. paramesonephric, duct). Importance : M. Immune System * If a mother should take an Third trimester : androgen-like substance during this - IgG maternal antibodies cross the stage of pregnancy, a child who is placenta into the fetus chromosomally female would appear - give the fetus temporary passive more male than female at birth. immunity against diseases for * If deficient testosterone is secreted by which the mother has antibodies. the testes, both the müllerian duct and - includes poliomyelitis, rubella, the wolffian duct could develop rubeola, diphtheria, tetanus, (pseudohermaphroditism, or intersex ). infectious parotitis, hep B, and pertussis. K. Urinary System - fetus is susceptible to herpes - End of 4th week : kidneys are virus as there is little or no present but are not essential as immunity at all the placenta clears the fetus of - The level of immunity peaks at waste products. birth and then decreases over the - 12th week : urine is formed next 8 months while the infant - 16th week: urine is excreted into begins to build up his or her own the amniotic fluid stores of IgG, IgA and IgM. - At term : fetal urine is being 2 months : excreted at the rate of 500 - immunization is started as mL/day. passive immunity declines - Oligohydramnios ( amount of amniotic fluid that is less than normal ) suggests that fetal Milestones of Fetal Growth and - External genitalia are present, but Development sex is not distinguishable by simple observation. Day 1: Fertilization - all human - The primitive tail is regressing. chromosomes are present; unique - Abdomen appears large because human life begins. the fetal intestine is growing Day 6: embryo begins implantation in rapidly. the uterus. - Sonogram shows a gestational Day 22: heart begins to beat with the sac, diagnostic of pregnancy. child's own blood, often a different type than the mothers'. Weeks 9 and 10: Teeth begin to form, Week 3: By the end of the third week fingernails develop. The baby can turn the child's backbone spinal column and his head, and frown. The baby can nervous system are forming. The liver, hiccup. kidneys and intestines begin to take Weeks 10 and 11: The baby can shape. "breathe" amniotic fluid and urinate. Week 4: Length: 0.75 to 1 cm Week 11: the baby can grasp objects Weight : 400 mg placed in its hand; all organ systems are Week 5: Eyes, legs, and hands begin to functioning. The baby has a skeletal develop. structure, nerves, and circulation. Week 6: Brain waves are detectable; Week 12 (First trimester): mouth and lips are present; fingernails - The baby has all of the parts are forming. necessary to experience pain, Week 7: Eyelids, toes form, nose including nerves, spinal cord, and distinct. The baby is kicking and thalamus. Vocal cords are swimming. complete. The baby can suck its Week 8: Every organ is in place, bones thumb. begin to replace cartilage, and Length : 7 to 8 cm fingerprints begin to form. By the 8th Weight :45 g week the baby can begin to hear. - Sex is distinguishable by outward - Length : 2.5 cm ( 1 in ) appearance - Weight : 20 g - Kidney secretion has begin - Organogenesis is complete. - Heartbeat is audible through - The heart, with septum and Doppler valves, is beating rhythmically. Week 14: At this age, the heart pumps - Facial features are definitely several quarts of blood through the body discernible. every day. - Arms and legs are developed. Week 15: The baby has an adult's taste buds. Month 4: Bone Marrow is now beginning - Pupils are capable of reacting to to form. The heart is pumping 25 quarts light. of blood a day. By the end of month 4 - Achieved a practical low-end age the baby will be 8-10 inches in length of viability if they are cared for in and will weigh up to half a pound. a modern intensive care facility Week 17: The baby can have dream and has a weight of 601 g. (REM) sleep. - Hearing can be demonstrated by Week 19: Babies can routinely be saved response to sudden sound. at 21 to 22 weeks after fertilization, and Months 7 through 9 - Eyeteeth are sometimes they can be saved even present. younger. - The baby opens and closes his Week 20: The earliest stage at which eyes. Partial birth abortions are performed. At - the baby is using four of the five 20 weeks the baby recognizes its' senses (vision, hearing, taste, mothers voice. and touch.) Length : 25 cm - He knows the difference between Weight : 223 g waking and sleeping, and can - Spontaneous fetal movements relate to the moods of the mother. can be felt by the mother - The baby's skin begins to thicken, - Antibody production is possible. and a layer of fat is produced and - Hair forms extending to include stored beneath the skin. eyebrows and hair in the head. - Antibodies are built up, and the - Meconium is present in the upper baby's heart begins to pump 300 intestine. gallons of blood per day. - Brown fat starts to develop - Approximately one week before - Vernix caseosa begins to form. the birth the baby stops growing, End of 24th Gestational week (Second and "drops" usually head down Trimester) - The baby practices into the pelvic cavity. - breathing by inhaling amniotic End of 40th Gestational week fluid into its developing lungs. Length: 48 to 52 cm The baby will grasp at the Weight: 1,800 to 2,700g ( 5 to 6 lb) umbilical cord when it feels it. - Fetus kick actively - Most mothers feel an increase in - Fetal hemoglobin begins its movement, kicking, and hiccups conversion to adult hemoglobin from the baby. - Vernix caseosa is fully formed. - Oil and sweat glands are now - Creases of the soles of the feet functioning. cover at least two thirds of the Length: 28 to 36 cm surface. Weight: 550g MEASUREMENT of the LIFE of for example : Jan = 1 April = 4 FETUS Feb = 2 May = 5 and so forth. Ovulation age - For the first 3 months of the year, Gestational age – measured from the add 12 to the numerical value. first day of the last menstrual cycle for example : January : 1 + 12 = 13 February : 2 + 12 = 14 Lunar mos – 4 weeks period March : 3 + 12 = 15 Trimesters – 3 mos period Lunar mos – 10 mos (40 wks or 280 days) Determination of Estimated Birth Date - Traditionally, this date has been referred to as the estimated date of confinement ( EDC). - Changed to EDB as women are no longer “confined’ after childbirth. - If fertilization occurred early in a menstrual cycle, the pregnancy will probably end “early” - If ovulation and fertilization occurred later in the cycle, the pregnancy will end “late”. - Because of these, a pregnancy ending 2 weeks before or 2 weeks after the calculated EDB is considered. Estimating Age of Gestation Nagele’s Rule : standard method to predict the length of pregnancy. 1. Determine the last normal menstrual period (LMP). 2. Consider the FIRST DAY of the LMP. 3. Consider the month in numerical terms. ASSESSMENT OF GROWTH AND B. Estimating Fetal Growth DEVELOPMENT a. Estimating Fundic Height by - IMPORTANCE: McDonald’s Method ( indicator of uterine * Fetal growth and development can be size in early pregnancy) compromised if : - a fetus has a metabolic or EQUIPMENT : A centimeter tape chromosomal disorder that interferes measure with normal growth, PROCEDURE : - if the supporting structures such as 1. Explain the procedure to the mother. the placenta or cord do not form 2. Ask the mother to empty her bladder. normally - A full bladder displaces the - or if environmental influences, such uterus causing an inaccurate as cigarette smoking or alcohol measurement. consumption interfere with fetal growth. 3. Position mother on dorsal recumbent. 4. Drape. Nursing responsibilities: 5. Measure the distance abdominally from the top of the symphysis pubis over 1. Seeing that a signed consent form the curve of the abdomen to the top of has been obtained as needed. the uterine fundus. 2. Scheduling the procedure Fundic height ( FH ) in cm correlates 3. Explaining the procedure to the well with weeks of gestation between woman and her support person 20-31 weeks. 4. Preparing the woman physically and psychologically 5. Providing support during the procedure 6. Assessing both fetal and maternal responses to the procedure 7. Providing any necessary follow-up care 8. Managing equipment and specimens LIMITATION: - inaccurate in women with obesity, A. Health History polyhydramnios and uterine fibroids. 1. nutritional intake 2. personal habit ESTIMATING GESTATIONAL AGE BY 3. any accidents or experienced MCDONALD’S RULE intimate partner abuse This knowledge is exceedingly vital in the event of a high-risk pregnancy. PROCEDURE: how to assess fetal movement: 1. Explaining the procedure to the client. - let the mother lie in recumbent 2. Have the woman void. position after a meal 3. Measure the fundal height (FH) - record how many fetal using movements she feels over the - McDonald’s Method ( from the next hour. ( min. twice every 10 symphysis pubis to the top of the min or an average of 10-12 fundus ). x/hour) - 4. Compute using the McDonald’s - if less than 10 movements let the Rule : mother repeat the test for the next half hour. - if still less within two hours – call healthcare provider another protocol b. Cardiff method (count-to-Ten) - the mother records the time interval it takes for her to feel 10 fetal movements. Usually, this occurs within 60 minutes. 2. Fetal Heart Rate ( FHR ) FHR beat - 120 to 160 per minute whole pregnancy - can be heard and counted as early as 10th to 11th week of pregnancy by doppler tech. - fetal heart rate of less than 90 bpm is Assessing Fetal Well-Being high risk for miscarriage at 5 to 8 weeks C. Assessing Fetal Well-Being of pregnancy Fetal movement – a. Sandovsky method : felt by the 3. Rhythm Strip Testing mother ( quickening ) begins - Assessment of the fetal heart rate approximately 18 to 20 weeks of for whether a good baseline rate pregnancy and peaks at 28 to 38 weeks. and long-and-short term - a healthy fetus moves at least variability are present 10x/day. Baseline reading: refers to the average rate of the fetal heartbeat per minute  - Short-term variability (also called can be used as screening procedures in beat-to-beat variability) denotes all pregnancies the small changes in rate that occur from second to second if - If a 20-minute period passes the fetal parasympathetic without any fetal movement, it nervous system is receiving may mean only that the fetus is adequate oxygen and nutrients. sleeping. - Long-term variability denotes the - If the mother is given an oral differences in heart rate that carbohydrate snack, such as occur over the 20-minute time orange juice, her blood glucose period level may increase enough to Variability is categorized as: cause fetal movement. a. Absent ( none apparent) b. Minimal ( extremely small Vibroacoustic Stimulation fluctuations) - A specially designed acoustic c. Moderate ( amplitude range of stimulator is applied to the 6-25 beats per minute ) mother’s abdomen to produce a d. Marked ( amplitude range over sharp sound of approximately 80 25 beats) decibels at a frequency of 80Hz, - Average fetus moves about twice startling and waking the fetus. every 10 minutes and movement - If a spontaneous acceleration has causes the heart rate to increase. not occurred within 5 minutes, There will typically be two or this could be repeated again at more instances of fetal heart the end of 10 minutes if no acceleration in a 20-minute spontaneous movement occurs rhythm strip Contraction Stress Testing Nonstress Testing - Nipple stimulation as a source of - Measures the response of FHR oxytocin is used for contraction to fetal movements stress testing - If no increase in bpm is - Gentle stimulation of the nipples noticeable in fetal movement, releases oxytocin in the same poor oxygen perfusion of the way as happens with fetus is suggested breastfeeding - This test is done for 10-20 - With external uterine contraction minutes and fetal heart rate monitors in place, the baseline FHR is Both rhythm strip and nonstress testing obtained. are noninvasive procedures and cause no risk to either mother or fetus, they  - 3 contractions with a duration of - To confirm the presence, size, 40 seconds or longer before the and location of the placenta and test can be interpreted amniotic fluid - The test is negative (normal) if no - To establish that a fetus is FHR decelerations are present growing and has no gross with contractions anomalies, such as - It is positive (abnormal) if 50% or hydrocephalus, anencephaly more of the contractions cause a (congenital absence of all or late deceleration major parts of the brain), or spinal cord, heart, kidney and bladder defects - To establish sex if a penis is revealed - To establish the presentation and position of the fetus - To predict maturity by measurement of the biparietal diameter of the head - - It is also used to discover Ultrasonography complications of pregnancy, such - Ultrasound is a technique that as the presence of an intrauterine uses sound waves to show a device, hydramnios or picture of a baby (fetus) in the oligohydramnios, ectopic uterus. Because it uses sound pregnancy, missed miscarriage, waves than radiation, ultrasound abdominal pregnancy, placenta is safer than x-rays previa, premature separation of - Ultrasound provides important the placenta, coexisting tumors, information about the health of multiple pregnancy, or genetic the fetus and conditions in the abnormalities such as Down uterus. This information can syndrome. guide a health care provider’s - Fetal anomalies such as neural plans for a pregnant woman and tube disorders, diaphragmatic improve the outcome of hernia, or urethral stenosis can pregnancy. also be diagnosed. It can be used for the following - Fetal death can be revealed by a purposes: lack of heartbeat and respiratory - To diagnose pregnancy as early movement. After birth, a as 6 weeks of gestation sonogram may be used to detect  a retained placenta or poor - REAL-TIME MODE - involves the uterine involution in the mother. use of multiple waves that allow - Intermittent sound waves of high screen pictures to move, and frequency are projected toward even movement of the the uterus by a transducer placed extremities, such as bringing a on the abdomen hand to the mouth to suck a (TRANSABDOMINAL) or in the thumb, can be seen. A parent vagina (TRANSVAGINAL). The who is in doubt that her fetus is sound frequencies that bounce well or whole can be greatly back can be displayed on an reassured by viewing a real-time oscilloscope screen as a visual sonogram. image. The frequencies returning from tissues of various thickness BIPARIETAL DIAMETER and properties present distinct Two other measurements made by appearances. A permanent sonography are: record can be made of the scan. - head circumference (34.5 cm indicates a 40-week fetus) 11. Triple Screening femoral length -- Measures the - or analysis of three indicators ( longest bone in the body and MSAFP, unconjugated estriol, and hCG) reflects the longitudinal growth of - done to yield even more reliable the fetus. Its usefulness is similar results. to the BPD. It increases from 12. Chorionic Villi Sampling about 1.5 cm at 14 weeks to - a biopsy and chromosomal about 7.8 cm at term. analysis of chorionic villi that is done at 10 to 12 weeks of pregnancy. ULTRASONOGRAPHY ULTRASONOGRAPHY DOPPLER UMBILICAL VELOCITY - The intricacy of the image - Measures the velocity (speed or obtained depends on the type of rate) at which red blood cells in process used. the uterine and fetal vessels are - B-MODE SCANNING - most traveling. frequently used and produces - Assessment of the blood flow what people generally refer to as through uterine blood vessels is Sonogram. This mode allows helpful in determining the patterns to merge and form a vascular resistance present in picture, similar to a black and women with diabetes or white television picture hypertension of pregnancy and (gray-scale imaging). whether resultant placental insufficiency has occurred.  - Because it will limit the number of ELECTROCARDIOGRAPHY nutrients that can reach the fetus, - Fetal ECGs may be recorded as decreased velocity is an early as the 11th week of important predictor of poor pregnancy. neonatal outcome. - But ECG is inaccurate before the 20th week, because fetal electrical conduction is so weak PLACENTAL GRADING that it is easily masked by the - Based particularly on the amount mother's ECG tracing. of calcium deposits in the base of - It is rarely used unless specific the placenta, placenta can be heart anomaly is suspected. graded by ultrasound as: 0 = a placenta 12 to 24 weeks MAGNETIC RESONANCE IMAGING 2 = a placenta 30 to 32 weeks - MRI may be used to assess 3 = 36 weeks fetus. 1 = 38 weeks - The technique caused no harmful - A Grade 3 placenta suggests that effects to the fetus or mother the fetus is mature - MRI has the potential to replace or complement ultrasonography AMNIOTIC FLUID VOLUME as a fetal assessment technique ASSESSMENT - It may be most helpful is - The amount of amniotic fluid diagnosing complications such as present is an important fetal ectopic pregnancy or assessment, for a portion of the trophoblastic disease because fluid is formed by fetal kidney later in a pregnancy, fetal output. movement can obscure the - If a fetus is becoming stressed in findings. utero because the circulatory and kidney functions are failing, urine output, and consequently the MATERNAL SERUM volume of amniotic fluid also will ALPHA-FETOPROTEIN decrease. - Alpha-fetoprotein (AFP) is a - A decrease in amniotic fluid substance produced by the liver volume puts the fetus at risk for that is present in amniotic fluid compression of the umbilical cord and maternal serum. and consequent interference with - Traditionally assessed at the 15th nutrition. week of pregnancy, between 85 to 90% of neural tube defects and  80% of Down syndrome babies AMNIOCENTESIS can be detected by this method. - Amniocentesis is an easy - The level is abnormally high in procedure, but it can be the maternal serum (MSAFP) if frightening to a woman. It the fetus has an open spinal or involves penetration of the abdominal defect, because the integrity of the amniotic sac, there open defect allows more AFP to is also a risk for the fetus, appear. although this risk is low (less than - Although the reason is unclear, 0.5%) the level of AFP is low if the fetus - It can lead to hemorrhage due to has a chromosomal defect such penetration of the placenta, as Down syndrome. infection of the amniotic fluid, and - MSAFP levels begin to rise at 11 puncture of the fetus. It can lead weeks gestation and then to irritation of the uterus, causing steadily increase until term. premature labor. TRIPLE SCREENING - Analysis of three indicators: 14. Percutaneous MSAFP, unconjugated estriol, Umbilical Blood Sampling hCG - may be performed in place - the aspiration of blood from the of AFP testing alone to yield umbilical vein for analysis. more reliable results. - if fetus is found to be anemic, - As with the measurement of blood may be transfused using MSAFP, it requires only a simple the same procedure. venipuncture of the mother. CHORIONIC VILLI SAMPLING 15. Amnioscopy CVS - the visual inspection of the - is a biopsy and chromosomal amniotic fluid through the cervix analysis of chorionic villi that is and membranes with an done at 10-12 weeks of amnioscope ( a small fetoscope). pregnancy. - use to detect meconium staining. - Coelocentesis - transvaginal aspiration of fluid from the 16. Fetoscopy extraembryonic cavity, is an - fetus is visualized by inspection alternative method to remove through a fetoscope ( an cells for fetal analysis. extremely narrow, hollow tube inserted by amniocentesis technique).  - used for the following purposes: 1. to confirm the intactness of the spinal column. 2. to obtain biopsy samples of the fetal tissue and fetal blood samples 3. to perform elemental surgery 17. Biophysical Profile - combines five parameters (fetal reactivity, fetal breathing movements, fetal body movement, fetal tone, and amniotic fluid volume) into one assessment.