UNIT 2-3 PDF

“Antepartum” – before and to give birth -the period before childbirth -time between conception and onset of labor *Skipped Organogenesis The process by which the organs in the body develop from the embryonic germ layers during intrauterine life – occurring in first trimester; this is followed by g...

“Antepartum” – before and to give birth -the period before childbirth -time between conception and onset of labor *Skipped Organogenesis The process by which the organs in the body develop from the embryonic germ layers during intrauterine life – occurring in first trimester; this is followed by gastrulation -starts in the ampulla of the fallopian tube – sperm cell goes through the zona pellucida and merge its genetic materials (nucleus) with the egg cell – forming a zygote -fertilized egg travels through the fallopian tubes and undergoes several mitotic cell divisions -after the zygote is formed, eggs releases proteins to prevent other sperm from fusing with the egg again Cleavage – a series of rapid cell divisions occurring immediately after fertilization in the single celled zygote, leading to the formation of a multicellular structure called the morula – then the blastula, and eventually the blastocyst The blastula’s intracellular components are divided into 2 – trophoblast and embryoblast -the embryoblast becomes more clustered, forming into one side and leaving a cavity – the blastocoel -this is now the blastocyst Week 1 - fertilized egg is now a morula (16 cells - 32 cells) -cells of the morula are totipotent – can differentiate into all cell types (embryonic/non embryonic) -is nourished by nutrients stored in egg’s cytoplasm and uterine milk (endometrial secretions) -starts to arrange themselves into a blastocyst – arranges themselves into a fluid filled cavity (blastocoel) -blastocyst consists of the embryoblast (pluripotent), trophoblast (later becomes the chorion) -trophoblast secretes an enzyme surrounding the conceptus – breaking down the extracellular matrix and the uterine lining for implantation of the blastocyst ​ Hyaluronidase - breaks down hyaluronic acid, a key component of the extracellular matrix, this allows the blastocyst to invade the uterine tissue more easily ​ Collagenase - breaks down collagen fibers in the uterine tissue, allowing the blastocyst to penetrate deeper into the endometrium for successful implantation -happens in days 5 or 6 Upon implantation, the trophoblast fuse together with the endometrium to form the syncytiotrophoblast & the cytotrophoblast – the former grows into the endometrium and derives nutrition from it -this later forms as the placenta -the endometrium then envelopes the blastocyst Syncytiotrophoblast then secretes the Human Chorionic Gonadotropin (HCG) – the basis of urine pregnancy test – this instructs the corpus luteum to produce progesterone -secretes somatomammotropin, estrogen, and progesterone as well Inner langhan’s layer(?) Week 2 - the embryoblast starts to form a bilaminar disk called the hypoblast (ventral) and the epiblast (dorsal) in the middle -this happens upon implantation of the blastocyst -by the end of week 2, the 2 layers grow around the cavity – forming the yolk sac and the amnion Embryoblast forms a cavity called the amniotic cavity Week 3 - gastrulation begins -embryonic development during which 3 germ layers (ectoderm, mesoderm, and endoderm) forms; these layers give rise to all the tissues and organs of the body (organogenesis) -starts with a trilaminar structure -appearance of the primitive streak on the surface of the epiblast -epiblast cells migrate thru the primitive streak into the embryo -this displaces the hypoblast and becomes the endoderm -cells fills the opening between the the now endoderm and the epiblast, forming the mesoderm -and the remaining epiblast cells form the ectoderm Each of these germ layers differentiates to become different organs and tissues The ectoderm develops into: ​ Nervous system ​ Epidermis ​ Hair ​ Nails The mesoderm develops into: ​ Skeleton ​ Muscles ​ connective tissue ​ Heart ​ blood vessels ​ kidneys The endoderm develops into: ​ Gastrointestinal tract ​ Liver ​ Pancreas ​ Lungs Embryonic and Fetal structures Chorionic villi Development of the systems Respiratory system -24 to 28 weeks, alveoli and capillaries begin to form -3 months begins spontaneous respiratory practice movements -specific lung fluid with a low surface tension and low viscosity forms in alveoli to aid expansion -rapidly absorbed after birth -24th week, phospholipid substance (surfactant) is formed and excreted by the alveolar cells Nervous system -all parts of the brain (cerebrum, cerebellum, etc) forms in utero -5-6 years for age of brain maturity -eye and inner eye develop as projections of original neural tube -24 weeks, the ear is capable of responding to sound -eyes exhibit pupillary reaction on 28 weeks (7 mos) Digestive system -4th week, digestive tract separated from the respiratory tract -tract canalizes to become patent -Stenosis refers to the narrowing of the lumen -Atresia refers to closing of the lumen -proliferation of cells shed in the second recanalization forms the basis of meconium -16th week: collection of cellular waste, bile, fast, mucoproteins, portions of vernix caseosa -stool is sticky in consistency and appears black or dark green (from bile pigment) -The gastrointestinal tract is sterile at birth -needs to be breastfed immediately -Vitamin K is synthesized by bacteria -Vitamin K levels are low in the newborn -Liver is active throughout gestation -acts as a filter between incoming blood and fetal circulation -deposit site for fetal stores such as iron and glycogen -prevents hypoglycemia at birth -hyperbilirubinemia -does not prevent recreational drugs / alcohol ingested by mother from entering fetal circulation * Endocrine system* -as soon as endocrine organs mature in intrauterine life, function begins -fetal adrenal glands supply a precursor necessary for estrogen synthesis by the placenta -fetal pancreas produces insulin needed by the fetus -thyroid and parathyroid glands play vital roles in fetal metabolic function Urinary system 12th week - urine is formed and is excreted into the amniotic fluid Integumentary system -skin of a fetus appears thin and translucent -36 weeks subq fat begins to be deposited -2 weeks prior to delivery, mother stops eating too much Lanugo -soft downy hairs covering the skin that serves as insulation to preserve warmth in utero in a way -More lanugo of preterm, lesser lanugo if term baby Vernix caseosa -cheese like substance which is important for lubrication and warmth Cardiovascular system -one of the first systems that functions during intrauterine life – as early as week 4 -heartbeat and fetal blood starts to exchange with mother’s blood – as early as 3rd week / 24 days inside the uterus -6th to 7th week, develops the septum that divides the heart into chambers -heart valves begin to develop -heartbeat can be heard with a doppler instrument as early as 10th to 12th week of pregnancy -electrocardiogram may be recorded as early as 11th week -heart rate of a fetus is affected by oxygen level, activity, and circulating blood volume Maternal fetal circulation -Gas exchange occurs in placenta; since fetus’ lungs are fluid filled (not functioning) -upon delivery high pressure + high pressure = first breath 3 MAJOR VASCULAR SHUNTS IN THE FETUS ​ Ductus venosus – between the umbilical vein and the inferior vena cava ​ Foramen ovale – between the right and left atrium ​ Ductus arteriosus – between the pulmonary artery and descending aorta Process Placenta > umbilical vein > Ductus Venosus > Inferior Venacava > Right atrium > Foramen Ovale > Left atrium > Left ventricle > Aorta > Body > Superior Venacava > >Right atrium> Right ventricle > Pulmonary artery > Ductus arteriosus > Descending aorta > Umbilical artery > Placenta Immune System -20th week Immunoglobulin G (IgG) maternal antibodies cross the placenta into the fetus -24th week gives a fetus temporary passive immunity against diseases for which the mother has antibodies Little to no immunity against herpes virus, chickenpox, cold sores, genital herpes STAGES OF FETAL DEVELOPMENT End of 1st month (4 gestational weeks) -length is 0.72 cm / weight is 400 mg -spinal cord is formed and fused at the midpoint -lateral wings that will form the body are folded forward to fuse at midline -head folds forward, becomes permanent (this is about ⅓ of the entire structure) -back is bent to the point the head almost touches the tail -rudimentary heart appears as a prominent bulge on the anterior -arms / legs are budlike structures -rudimentary ears, eyes, nose are discernable End of 8th gestational week -length is 2.5 cm / weight is 20 g -Organogenesis is complete -heart, with septum and valves – beating rhythmically -facial features are discernable -arms / legs have developed -external genitalia forming; sex is not yet distinguishable by observation -primitive tail is regressing -abdomen bulges forward (fetal intestine growing rapidly) -ultrasound shows gestational sac, diagnostic of pregnancy End of 12th gestational week -length is 7-8 cm / weight is 45 g -nail beds forming on toes and fingers -spontaneous movements are possible; are too faint to be felt by mother -reflexes such as babinski, etc., are already present -bone ossification centers begin to form -tooth buds become present -sex is determined by outward appearance -urine secretion begins; may not be evident in amniotic fluid -heartbeat heard using doppler technology End of 16th week -length is 10-17 cm / weight 55 - 120 g -fetal heart sounds audible using stethoscope -lanugo well formed -liver and pancreas are functioning -fetus actively swallows amniotic fluid – intact but uncoordinated swallowing reflex -sex can be determined by ultrasound End of 24th week -length is 28-36 cm / weight 550 g -meconium is present as far as the rectum -active production of lung surfactant -eyebrows and lashes become well defined -eyelids previously fused in 12th week now open -pupils are capable of retracting to light -at this point, has achieved low end age of viability -hearing can be demonstrated by response to sudden sound (moro reflex?) End of 20th gestational week -length is 25 / weight is 223 g -spontaneous fetal movements sensed by the mother -antibody production is possible -hair forms on head extending to include the eyebrows -meconium is present on the upper intestine -BAT aids in temp regulation at birth; located behind kidneys sternum and posterior neck -vernix caseosa begins to form and cover the skin -passive antibody transfer from mother to fetus begins -definite sleeping and activity patterns are distinguishable -fetus developed biorhythms that guides sleep/wake patterns throughout life End of 28th week -length is 35-38 cm / weight 1200 g -lung alveoli begin to mature; surfactant is demonstrated in amniotic fluid -testes begins to descend into scrotal sac from lower abdominal cavity -blood vessels of the retina formed; extremely thin and susceptible to damage from high oxygen concentrations End of 32nd week -length is 38-43 cm / weight 1600 g -subq fat begins to be deposited -fetus responds by movement to sounds from the mother or from outside -active moro reflex present -iron stores, beginning to be developed(?) -fingernails grow to reach the end of fingertips End of 36th week -length is 42-48cm / weight 1800 - 2700 g -body stores of glycogen, iron, carbohydrate and calcium are deposited -addt amounts of subq fats are deposited -sole of the feet has only 1 or 2 criss cross creases, compared with the full crosscross pattern that is evident in term -amount of lanugo begins to diminish -most babies start to turn to a vertex presentation during this month End of 40th week -length is 48-52 cm / weight 3000g -fetus kicks actively, hard enough to cause discomfort for the mother -fetal hemoglobin begins its conversion to adult hemoglobin -vernix caseosa is fully formed -fingernails extend over the fingertips -creases on the soles cover at least ⅔ of the surface Multifetal pregnancies -a pregnancy involving 2 or more fetuses -twins may originate several ways: identical twins (monozygotic) or fraternal twins (dizygotic) -this happens when more than one egg is fertilized Pregnancies involving more than 2 fetuses may occur in: Monozygotic -happens with one sperm and one egg; later will split into embryos -all will be identical -Multi-zygotic -multiple eggs are fertilized by multiple sperm cells; leading to the formation of several embryos (up to 5 – quintuplets) -often associated with fertility drugs in which the ovary matured and released many eggs in the same cycle How do conjoined twins occur? Thoracopagus? Ischiopagus Principles of Fetal immunology -during the third trimester, passive immunity to some diseases is provided by the mother -diseases that the fetus receives temporary immunity from include: ​ Rubella ​ Diphtheria ​ Measles ​ Poliomyelitis ​ Tetanus ​ Mumps Passive immunity – “pinasa ng nanay sa bata” -this is short term in infants -must begin immunization against the above diseases by the age of 2 months Confirmation of pregnancy Presumptive (subjective) symptoms -not proof, is subjective; “presume” ​ Period absent (amenorrhea) ​ Really tired ​ Enlarged breast ​ Sore breast ​ Urination increased ​ Movement of fetus in uterus ​ Emesis and nausea (morning sickness) Probable signs Increased suspicion, but still no proof; no subjective data Is “probable” ​ Positive pregnancy sign ​ Returning of the fetus (ballottement) ​ Outline of fetus can be palpated ​ Braxton hicks contractions (false labor contractions that won't result in cervical dilations) ​ A softening of the cervix (Goodell’s sign) ​ Bluish discoloration of the vulva (Chadwick’s sign) ​ Lower uterine segment becomes soft (Hegar’s sign) ​ Enlarged uterus Positive signs of pregnancy No subjective data; are definitive signs of pregnancy ​ Fetal movements felt by professionals, palpitation of fetal outline ​ Electronic device picks up Fetal heart tone ​ Delivery of the baby ​ Ultrasounds detection ​ Sees visible movement of the baby by professionals Assessing fetal maturity and well-being Indications for assessing fetal maturity includes: ​ Determining the appropriate time for inducing labor ​ Avoiding prematurity ​ Guarding the high risk mother ​ Varieties of tests of the fetus status are of value in monitoring its wellbeing ​ Evaluation of fetal maturity/wellbeing is essential in the management of high risk pregnancies Examples of assessments are divided into 2 Invasive Amniocentesis ​ Withdrawal of amniotic fluid by insertion of a needle through the abdomen and uterine walls ​ Possible after 14th week; when there is sufficient fluid for the procedure ​ Information obtained from procedure include: color of fluid, detection of fetal chromosomal anomalies, helps evaluate probability of sex-linked genetic disorders, indicates fetal maturity or in-born errors Percutaneous Umbilical blood sampling ​ Aspiration of blood from umbilical vein; after it is located by sonology / ultrasound ​ Obtained fetal blood is submitted to a Kleihauer-betke test – measures the difference between adult and fetal hemoglobin and helping assess the amount of fetal maternal hemorrhage ​ Blood gases, Karyotyping, and Direct coombs test can also be done from this procedure Fetoscopy -a medical procedure used to visually examine the fetus in the womb during pregnancy, using an instrument called “a fetoscope”; also a procedure used for surgery and sample collection ​ 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 ​ Repair a neural tube defect Maternal serum -can reveal information about the pregnant woman as well as the fetus -refers to the liquid component of a pregnant woman's blood that remains after the removal of cells (such as RBC, WBC, platelets) – this is the plasma portion of the blood containing proteins, hormones, electrolytes, antibodies, and other substances Methods include: ​ Maternal serum alpha fetoprotein – 85 and 95 of neural tube anomalies and 80% of babies with Down syndrome can be detected by this method ​ Fetal gender -can be determined as early as 7 weeks by maternal serum analysis -analysis of fetal gender with chromosomes (Y chromosome or its absence) ​ Associated plasma protein A ​ Quadruple screening -one of the common maternal serum tests used today Non Invasive Non-stress test (NST) -prenatal test used to assess fetal heart rate and its response to fetus’ movement -Non reactive NST means that with movement during the testthe fetal heart rate did not show expected acceleration -it assesses ability of the placenta to supply fetal needs in a normal daily uterine environment -evaluates sufficient placental functioning; fetus should demonstrate acceleration in heart heart with movement -lack of heart rate acceleration indicates need for further testing -to screen high risk pregnancies; where placental compromise is anticipated, pregnancy induced hypertension, gestational diabetes, intrauterine growth retardation, maternal complaints of decreased fetal movement -mother is instructed to press a button when she feels the fetus move Non invasive: methods of contraction production Oxytocin challenge test (OCT) -evaluates how fetus responds to uterine contractions; assesses FHR during simulated labor -a dilute of I.V solution of oxytocin -administered until a contraction pattern is developed -when sufficient information is obtained, the medication is turned off -the oxytocin challenge test evaluates the ability of the placenta to -supply fetal needs in a stressed environment -contractions, such as those of labor, are a stress on the pregnancy -OCT is used to evaluate high risk pregnancy where placental compromise is suspected -OCT is often applied and used to evaluate pt’s who were listed under NST Unacceptable results include -decrease or deceleration in heart rate during contractions Breast Stimulation test (BST) -involves stimulation of the nipples by rubbing, causing the posterior pituitary gland to release a hormone called oxytocin = contractions Contraction stress test (CST) -evaluation is done in the presence of naturally occurring contractions -a means of evaluating respiratory function (oxygen/carbon dioxide exchange) in the placenta Ultrasonography (UTZ) -sound waves against solid objects – this is a much used tool for fetal health assessments -a medical imaging technique that uses high frequency sound waves to create images of inside of the body -diagnose pregnancy as early as 6 weeks gestation -confirm presence, size, location of placenta and amniotic fluid -establish a fetus is growing and has no gross anomalies -establish the sex if penis is revealed -establish presentation and position -predict gestational age by measurement of head to rump -fetal death can be revealed by lack of FHR and respirations -post delivery, this can also be used to detect a retained placenta or poor uterine involution Magnetic Resonance imaging (MRI) -apparently causes no harmful effects to the fetus or woman -potential to replace or complement ultrasonography as a fetal assessment -can identify structural anomalies or soft tissue disorders Physical changes during pregnancy Reproductive system ​ Uterus increases in size ​ Capacity of uterus expands to accomodate a 7 pound fetus and placenta, umbilical cord, 500-1000 ml of amniotic fluid ​ Abdominal contents are displaced to the sides ​ Growth of the uterus occurs at a steady, predictable pace ​ Measurement of fundal height is important and is noted ​ growth that is too fast or slow is an indication of problems ​ Size of uterus peaks at 38 weeks gestation ​ Uterus might drop slightly as fetal head settles into pelvis “lightening” Cervix -undergoes a marked softening (Goodell’s sign) -operculum is formed in the cervical canal -bloody show Vagina -normal light pink to purple hue (Chadwicks) Ovaries -FSH ceases activity -corpus luteum enlarges during early pregnancy; may forma cyst on the ovary even The Breasts -early pregnancy, may feel full or tingle -increases in size as pregnancy advances -areola darkens, diameter increases -montgomery glands of the areola -surface vessels of the breasts may become visible -16th week (2nd tri) breasts produces colostrum -N.I: advice mother to wear a good supporting bra Skin Linea negra -hormone induced pigmentation -from the umbilicus to the symphysis pubis, may extend as high as the sternum Striae Gravidarum -separation within underlying connective tissue of the skin -occurs over areas of maximal stretch -fades after delivery (usually) Chloasma (mask of pregnancy) -brownish hyperpigmentation of skin over the face and forehead Sweat glands -sweat gland throughout the body usually increases Circulatory system Blood volume -increases gradually -decreased conc. of RBC and hemoglobin -anemia if hemoglobin falls below 10.5, hematocrit below 30% -improves the placental performance -increased blood flow compensates for hypertrophied (increase in size or growth) vascular systems of the enlarged uterus Cardiac output -increases about 30 percent during 1st and 2nd trimester to accommodate for hypervolemia -N.I: pt with heart disease need to get plenty of rest and to report any shortness of breath or unusual symptoms to the physician Blood pressure -normally will not rise -N.I: pt’s BP should be checked carefully and often -MUST be done under the same circumstances Venous return -lower extremities often hampered (in the last months of pregnancy) -N.I: frequent and adequate rest is advised, elevate feet and legs while sitting, dont lie in supine position Body Temperature -slight increase in body temperature in early pregnancy is noted -this returns to normal about 16th week of gestation -pt may feel a little warmer or experience hot flashes Urinary system -increase in urinary output and decrease in specific gravity -pt may experience urine stasis and pyelonephritis in right kidney -frequent urination Skeletal system -realignment of spinal curvatures during pregnancies; causes waddling gait -slight relaxation and increased mobility of the pelvic joints; allows stretching at the time of delivery of the infant Gastrointestinal system -enlargement of the uterus as it rises out of the pelvic cavity displaces the stomach, intestines, and other adjacent organs -slowed peristalsis -increased chance of nausea and heartburn -increased chance of constipation -N.I: eat small, frequent meals, well balanced diet high in protein, iron, and calcium for fetal growth -fiber and fluids to prevent constipation -dont lie flat 1-2 hrs after eating Selected Glands of the Endocrine System Parathyroid gland -increases in size slightly Anterior pituitary -at birth, this will begin to secrete prolactin = stimulates production of breast milk Posterior pituitary -near the end of term, this will begin to secrete oxytocin that was produced in the hypothalamus and stored there -serves to initiate labor Placenta -acts as temporary endocrine gland during pregnancy -produces large amounts of estrogen and progesterone by 10-12 weeks -serves to maintain growth of uterus, helps to control uterine activity -responsible for the many maternal changes in the body Body weight -normal weight gain is 24-30 pounds Nursing implications -there is a slight loss of pounds during early pregnancy if the pt experiences much emesis and nausea -gains 2-4 pounds by the end of 1st trimester -gain a pound per week during 2nd and 3rd trimester -monitor weight gain and blood pressure -lack of significant weight gain, an indication of intrauterine growth retardation of the infant -pt with multiple fetuses requires higher caloric diet and higher weight gain Psychological changes during pregnancy ​ Ambivalence -patient’s simultaneous attraction for and against the pregnancy -not to say she doesnt feel good about the pregnancy -even though may be experiencing doubt in some ways, mother may also be experiencing joy and excitement as well as happiness and anticipation ​ Fear and anxiety -refers to mother being concerned for her own health and health of the baby ​ Introversion or narcissism -pt becomes more concerned for herself -may be preoccupied with her own thoughts and feelings ​ Uncertainty -before acceptance of pregnancy, mother asks “am i really pregnant?” -this may last until pregnancy is diagnosed -”Quickening” usually a big milestone in the process of acceptance Factors that may influence the extent of these reactions Emotional reactions of a patient may have some bearing on the following factors -is it a planned or a wanted pregnancy? -is it the first pregnancy? -what experiences and memories does the pt have about previous pregnancies Psychological changes in pregnancy during first trimester Behaviors the mother may engage in: -displays a sense of ambivalence to the pregnancy -fantasizes about the pregnancy -role playing -increased concern for financial and social problems -decreased interest in sex due to changes in body Psychological changes in pregnancy during the second trimester Mother develops a sense of well being -body becomes adjusted to hormonal changes -early discomforts of pregnancy have subsided -usually, has adjusted psychologically to the realities and inconveniences that accompany pregnancy -fears have subsided, at least temporarily “Quickening” is experienced -mother can feel life inside her – this fetal movement confirms pregnancy -father can also feel this, he can then identify with the reality of pregnancy and accept Fetus heartbeat is heard Both parents display an interest in fetal growth and development Interest in the process of labor and delivery is expressed -may enroll in classes about childbirth and read related literature Mother may have wide mood swings -may be happy or sad for no apparent reason Mother may tend to be an introvert or to focus on herself as the center of attention -concentrate on her own needs and needs of the fetus -reflects on her own childhood and her relationship with he mother -preoccupied with her own thoughts and feelings Changes in sexuality -increased interest in sex -increase in sexual fantasies and dreams, increase in vaginal lubrication Psychological changes during the third trimester Altered self image -going from feeling special, beautiful, and pretty to being awkward, unsexy, and feels fat Fear -dreams about the infant and what the future holds -concerned for the health of her baby -concerned for her own safety and her performance during labor and delivery Aggravation -aggravated over things she cant do for herself due to her size Fatigue -becomes tired easily Obsession -concerned with delivery Wondering -wonders what kind of parent she will be >Adjustments of father during pregnancy >adjustments of single mother during pregnancy >Factors influencing the role of the unwed father >Factors influencing the role of the unwed mother and father >Special needs of siblings -can be found on week 6