Fetal Development Stages (Weeks 2-40) PDF

ORIGIN AND DEVELOPMENT OF ORGAN SYSTEM  GERM LAYERS Entoderm Mesoderm Ectoderm  GERM LAYERS Entoderm  Linings of pericardial, pleural and peritoneal cavities, linings of GIT and RT  Tonsils  Parathyroid  Thyroid  Thymus gland  Lower urinary...

ORIGIN AND DEVELOPMENT OF ORGAN SYSTEM  GERM LAYERS Entoderm Mesoderm Ectoderm  GERM LAYERS Entoderm  Linings of pericardial, pleural and peritoneal cavities, linings of GIT and RT  Tonsils  Parathyroid  Thyroid  Thymus gland  Lower urinary system  GERM LAYERS Mesoderm  Supporting structures of the body  Dentin of teeth  Upper portion of the urinary system  Reproductive system  Heart  Circulatory system  Blood cells  Lymph vessels  GERM LAYERS Ectoderm  CNS  PNS  Skin  Hair  Nails  Sebaceous glands  Sense organs  Mucous membranes of anus, mouth, nose  Tooth enamel  Mammary glands  GERM LAYERS  Blastocyst  Rubella infection  All organ systems 8 weeks (organogenesis)  CARDIOVASCULAR SYSTEM  16th day: single heart tube forms  24th day: heart starts to beat  6th or 7th week: development of septum  7th week: development of valves  11th week: ECG (20th week more accurate)  10-12th week: Doppler UTZ  20th week: Stethoscope DIFFERENCES OF FETAL CIRCULATION FROM EXTRAUTERINE CIRCULATION 1. The fetus derives oxygen and excretes carbon dioxide not from oxygen exchange: X lungs √ placenta 2. Blood does not enter the lungs while the fetus is in the uterus: X oxygen exchange √ supply the cells of the lungs themselves 3. Specialized structures present in the fetus shunt blood flow to supply the most important organs. DIFFERENCES OF FETAL CIRCULATION FROM EXTRAUTERINE CIRCULATION SHUNTS: 1. Ductus venosus = liver 2. Foramen Ovale = left side of the heart, aorta, other parts of the heart, the brain and kidney 3. Ductus Arteriosus = kidney and lower extremities Normal fetal heart beat – 120 to 160 beats/ minute  FETAL CIRCULATION  3rd week: fetal blood exchanges nutrients with maternal circulation  Special structures:  Ductus venosus - carry oxygenated blood = umbilical vein → inferior vena cava  Foramen ovale - connects the left and right atria, bypassing fetal lungs  Ductus arteriosus - carry oxygenated blood = pulmonary artery → aorta, bypassing fetal lungs  Umbilical vein - carry oxygenated blood (from placenta)  Umbilical artery - carry less oxygenated blood (to placenta)  Oxygenated blood enters the umbilical vein from the placenta Enters ductus venosus Passes through inferior vena cava Enters the right atrium Enters the foramen ovale Goes to the left atrium Passes through left ventricle Flows to ascending aorta to supply nourishment to the brain and upper extremities  Enters superior vena cava Goes to right atrium Enters right ventricle Enters pulmonary artery with some blood going to the lungs to supply oxygen and nourishment Flows to ductus arteriosus Enters descending aorta (some blood going to the lower extremities Enters umbilical arteries Goes back to the placenta Chorionic villi  FETAL CIRCULATION  Fetal circulation delivers the highest available oxygen concentration: ↑ Head and neck  ↑ Brain  ↑ Heart  ↑ Liver  ↑ Kidneys ↓ Abdominal organs ↓ Lower body  RESPIRATORY SYSTEM  3rd week - respiratory and digestive tract exist as a single tube  4th week - septum begins to divide the esophagus from trachea  Lung buds appear on the trachea  7th week - diaphragm divides the thoracic cavity from the abdomen completely  Ifthe diaphragm fails to close: stomach, spleen, liver, or intestines may herniate (diaphragmatic hernia)  RESPIRATORY SYSTEM  12th week: spontaneous respiratory practice movements  24th - 28th wk: alveoli and capillaries form  24th week: surfactant, a phospholipid, is excreted by alveolar cells  Lecithin : Sphingomyelin ration of 2:1 at 35weeks  ↓ surface tension on expiration - prevents lung collapse (improving infant’s ability to maintain respirations in the outside environment)  Amniocentesis - checks fetal maturity  NERVOUS SYSTEM  3rdto 4th wk: active formation of nervous system  All parts of the brain form intrauterine but matures at birth – 5-6 y/o (cerebrum, cerebellum, pons, and medulla oblongata)  24weeks: ear is capable of responding to sound, eyes exhibit pupillary reaction indicating sight  ENDOCRINE SYSTEM Fetal adrenal glands supply a precursor for estrogen synthesis by placenta Pancreas produces insulin needed by the fetus (insulin do not cross placenta) Thyroid and parathyroid glands has vital roles in metabolic function and calcium balance  DIGESTIVE SYSTEM  4th week: digestive tract separates from the respiratory tract  6th week: intestine  16th week: meconium is formed - cellular wastes, bile, fats, mucoproteins, mucopolysaccharides and portions of vernix caseosa - dark green / black and sticky in texture  GIT is sterile before birth (low vitamin K)  36 weeks: GIT secretes enzymes essential in carbohydrate and protein digestion  Liver – active throughout gestation; filter between incoming blood and fetal circulation; deposit site for fetal iron and glycogen MUSCULOSKELETAL SYSTEM week: cartilage prototypes provide position  2nd and support week: fetus can be seen moving through  11th the UTZ  12th week: CARTILAGE → BONES week: Mother usually feels fetal  20th movements  Quickening  REPRODUCTIVE SYSTEM  Child’s sex is determined at the moment of conception 8 weeks: chromosomal analysis  6th wk: gonads form (testes or ovaries)  Testes = (+) testosterone – male organs = (-) testosterone – female organs  Testes forms in the abdominal cavity but descends into the scrotal sac at 34th - 38th week (cryptorchidism)  URINARY SYSTEM  Formsintrauterine but not essential until birth (placenta)  4th week: rudimentary kidneys are present  12th week: urine is formed  16th week: urine is excreted in the amniotic fluid  At term: urine rate is at 500ml/day INTEGUMENTARY SYSTEM  Skinappears thin and translucent until adipose tissue forms at 36weeks  Lanugo* Function = insulation to preserve warmth in utero  Vernix caseosa * Function = lubrication; X skin from macerating LANUGO VERNIX CASEOSA  IMMUNE SYSTEM  20th week: IgG class of immunoglobulins cross the placenta  Temporary passive immunity against diseases (polio, rubella, rubeola, diphtheria, pertussis, tetanus, infectious parotitis, hepatitis B) until 8th month of life  Little / X immunity = herpes virus (chickenpox, cold sores, genital herpes)  IgA - found in colostrum and milk provides additional protection to the newborn MILESTONES OF FETAL GROWTH AND DEVELOPMENT  Fetal Development  WEEK 2 FERTILIZATION = thirty hours after conception = zygote =floats down from the fallopian tube and towards the uterus WEEK 3 - 4 = early formation of the central nervous system, backbone, and spinal column, gastrointestinal system, kidneys, liver, and intestines, and heart = hormones produced by the embryo stop the mother’s menstrual cycle = head folds forward and becomes prominent; head almost touches the tip of the tail = back is bent WEEK 5 = Length.75-1cm = Weight 400mg = day 21: heart begins to beat = brain has developed into 5 areas and some cranial nerves are visible. = arm and leg buds are visible = eyes, ears, lips, and nose = spinal cord grows faster than the rest of the body giving a tail like appearance which disappears as the embryo continues to grow. = rudimentary heart appears as a prominent bulge on anterior surface = placenta begins to provide nourishment for the embryo  WEEK 6-7 = major organs have all begun to form = own blood type = hair follicles and nipples form = knees and elbows are visible = facial features are also observable = eyes have a retina and lens = major muscle system is developed = MOVE  WEEK 8 = Length 2.5 cm (1 in) = Weight 20 g = embryo is reactive to its environment = hands and feet can be seen = embryo → fetus = facial features definitely noticeable = external genitalia are forming = primitive tail is regressing = abdomen bulges forward = heart with septum and valves beating rhythmically WEEKS 9-12 = Length 7-8 cm = Weight 45 g = heart and eyes almost completely developed = heart rate can be heard = red blood cells (liver) = face is well formed = eyelids will close = arms, hands, fingers, legs, feet, and toes are fully formed = nails and earlobes start to form = tooth buds develop in the gums = Testosterone (testes) = spontaneous movements are possible = some reflexes present = bone ossification = sex distinguishable by outward appearance = urine secretion begins WEEK 12 WEEKS 13-16 = Length 10-17 cm = Weight 55-120 g = heart rate can be heard = brain is fully developed = fetus can suck, swallow, and make irregular breathing sounds = fetus can feel pain = fetal skin is almost transparent = muscle tissue is lengthening = bones are becoming harder = eyebrows and eyelashes appear = active movements (kicks and even somersaults) = sex organs are visible (UTZ) = lanugo (16th week) = liver and pancreas are functioning = actively swallows amniotic fluid = urine present in amniotic fluid WEEK 16 WEEK 20 = Length 25 cm = Weight 223 g = “Quickening” = finger and toenails appear = lanugo covers the entire body = fetus can hear and recognize the mother’s voice = Vernix caseosa covers the skin = Meconium is present in the upper intestine = antibody production is possible = passive antibody transfer from mother to fetus = hair forms on head, eyebrows = brown fat begins to form behind kidneys, sternum, and posterior neck WEEK 20 WEEK 24 = Length 28-36 cm = Weight 550 g = hand reflex and startle reflex = footprints and fingerprints are forming = fetus practices breathing by inhaling amniotic fluid into its developing lungs = meconium is present as far as the rectum = active production of lung surfactants begin = pupils are capable of reacting to light = hearing can be demonstrated by response to sudden sound = eyelids now open = 601g = reached AOV WEEK 24 WEEKS 25 – 28 = length 35-38 cm = weight 1200 g = rapid brain development = nervous system is able to control some bodily functions = eyelids now open and close = 60% chance of survival (25 weeks) = 90% chance of survival (28 weeks) = lung alveoli begin to mature = testes begin to descend to lower scrotal sac from lower abdominal cavity (28th week) WEEK 28 WEEK 32 WEEKS 29 – 36 = Length 38-43 cm = Weight 1600 g = “little old man” appearance is lost = rhythmic breathing occurs, but the lungs are not yet mature = fetus sleeps 90-95% of the day. = survival rate is above 95% = active Moro reflex = birth position may be assumed = fingernails grow to reach end of fingertips WEEK 36 = Length 42-48 cm = Weight 1800-2700g (5-6 lb) = body stores of glycogen, iron, carbohydrates, and calcium are deposited = ↑ fats deposited = Sole of the foot has only one or two crisscross creases = ↓ lanugo WEEK 40 WEEKS 38 – 40 = Length 48-25 cm = Weight 3000 g (7-7.5 lbs) = full-term = X Lanugo (upper arms and shoulders) = hair on the baby’s head is now coarser and thicker = lungs are mature = at birth the placenta detaches from the uterus and the umbilical cord will be cut as the baby takes his first breaths of air = breathing will trigger changes in the heart and bypass arteries forcing all blood to now travel through the lungs = fetus kicks actively = Vernix fully formed = Creases on the soles of feet  Monozygotic -Begins with a single ovum and spermatozoa in the process of fusion or in one of the first cell divisions, the zygote divides into 2 identical individuals with same sex -Single ovum twins: 1 placenta: 2 amnions 1 chorion: 2 umbilical cords FRATERNAL TWINS (Dizygotic) Non-identical, as a result of fertilization of 2 separate ova and two spermatozoa 2 placenta: 2 chorion 2 amnion: 2 umbilical cord CHANGES IN PREGNANCY  PSYCHOLOGICAL CHANGES  Fortunate pregnancy is 9 months long.  fetus more time to mature  family more time to prepare emotionally  Superstitious beliefs about pregnancy:  Lifting arms over head = twist cord  Watching a lunar eclipse = birth deformities  Respect for person’s beliefs  X AFFECT FETUS!  COMMON PSYCHOLOGICAL PROBLEMS:  “If you hadn’t come along, I could have gone to college; I could have had a career”  “Brides are young, mothers are old”  “Children are time consuming”  “Pregnancy permanently stretch my abdomen and breasts”  “Rob me financially and ruin my chances of job promotion”  NURSING RESPONSIBILITIES:  Help the woman to cope with or adapt to stress.  Woman should feel secure in her relationship with the people around her, especially the father of her child.  “I want this baby”  Touch, caress, partner at prenatal visits and birthing room  Opportunity to express her feelings to a supportive person  “One door closes; another one opens”  “You’ll love having a baby in the house”  PSYCHOLOGICAL TASKS  1st trimester  Accepting the pregnancy  2nd trimester  Accepting the baby  3rd trimester  Preparing for the baby and end of pregnancy  ACCEPTING THE PREGNANCY  Recovery from shock of learning that she is pregnant  Ambivalence  50% of pregnancies are still unintended, unwanted, or mistimed  The earlier, the better to safeguard fetal health  1st missed menstrual period  Slight breast tenderness  Nausea and tiredness  Home pregnancy test kits  ACCEPTING THE BABY  Narcissism  Concentrate on what it feels like to be a parent  Anticipatory role playing and ↑ dreaming are common  Quickening  It’s a boy!  It’s a girl!  Shopping for baby’s clothes, setting crib  Partner preoccupied with work PREPARING FOR THE BABY AND END OF PREGNANCY  Impatient (ready for birth)  Nest-building activities (choosing a name)  Childbirth education classes EMOTIONAL RESPONSES  Ambivalence  Grief  Narcissism  change in activity, criticize husband’s driving, reduce risky activities PROTECT HER AND BABY  Introversion vs. extroversion – concentrate on one’s own body vs. becoming more active HEALTHIER THAN EVER BEFORE  Body image and boundary – related to narcissism and introversion EMOTIONAL RESPONSES  Stress – make decisions  maintain time management, support persons  Somatic symptoms experienced by the father during pregnancy simulating those of the pregnant mother  Couvade syndrome  N and V, backache  stress, anxiety, empathy pregnant woman  Emotional lability – mood changes  narcissism, hormonal changes, sustained increased E and P EMOTIONAL RESPONSES  Changes in sexual desire – ↑ / ↓ in libido  estrogen, threat to fetus, early labor  Changes in the expectant family  how to prepare an older sibling for the coming of the newborn (baby will be addition and will not replace them) PHYSIOLOGIC CHANGES OF PREGNANCY Local changes  Uterus, cervix, vagina, ovaries, breast Systemic changes  Integumentary, respiratory, circulatory, gastrointestinal, urinary, skeletal, endocrine, temperature changes, weight changes  UTERINE CHANGES ↑ size of the uterus Length 6.5 - 32 cm Depth 2.5 - 22 cm Width expands 4-24 cm Weight 50-1000 g Thickness early = uterine wall 1-2 cm end = uterine wall thins.5 cm Volume hold 7 lb + 1000 ml of AF  UTERINE CHANGES Growth is due to: 1. Formation of a few new muscle fibers in the uterine MYOMETRIUM 2. ↑ vascularity and dilation of blood vessels of uterus 3) development of the decidua  UTERINE CHANGES  Growth is due to: 1) Formation of a few new muscle fibers in the uterine MYOMETRIUM ↓ stretching of existing muscle fibers + extra fibroelastic tissue between fibers ↓ stretch = return to pre-pregnant state  UTERINE CHANGES Placenta grows ↓ 2) ↑ vascularity and dilation of blood vessels of uterus ↓ requires more and more blood for perfusion = before pregnancy = uterine blood flow 15-20 ml/min = end of pregnancy 500-750 ml/min 3) development of the decidua  12th week: a firm globe can be palpated under the abdominal wall  ASSESS: constant, steady, predictable increase in size  UTERINE CHANGES Uterus ↑ in size ↓ pushes intestines to the sides of the abdomen ↓ elevates the diaphragm and liver ↓ compresses the stomach ↓ ↑ pressure on the bladder  UTERINE CHANGES  Lightening  Primigravida: 2 weeks before term (38th weeks)  Multipara: unpredictable (labor begins)  Easier breathing  Hegar’s sign  extreme softening of the lower uterine segment  wall as thin as tissue paper  Bimanual exam: uterus more anteflexed, larger and softer to the touch than usual  6th week of pregnancy (2nd missed period)  Probable sign  UTERINE CHANGES  Ballottement = balloter  Bimanual exam: fetus bounce or rise in the amniotic fluid  16-20th week fetus is still small in relation to the amount of amniotic fluid present  Probable sign  UTERINE CHANGES Braxton Hicks contractions  “PRACTICE” contractions (↑ placental perfusion)  warm-up exercises for labor  Strong and noticeable in the last month of pregnancy = mistaken for labor contractions (false labor)  X cervical dilatation  Probable sign  UTERINE CHANGES Amenorrhea Absence of menstruation (suppression of FSH by rising estrogen levels) CAUSES = onset of menopause = uterine infection = worry, severe anemia or stress = athletes who train strenuously (long-distance runners) Presumptive sign  CERVICAL CHANGES ↑ vascular and edematous  Color: from a pale pink to a violet hue (↑ vascularity)  Goodell’s sign  softening of the cervix (↑ fluid between cells)  Non-pregnant:  Pregnant:  Before labor: butter or said to be “ripe”  Probable sign  CERVICAL CHANGES  Operculum Glands of endocervix ↓ hyperplasia and hypertrophy ↓ distend with mucus ↓ fills the cervical canal ↓ mucus plug  acts to seal out bacteria during pregnancy  VAGINAL CHANGES  White vaginal discharge (Leukorrhea) ↑ activity of vaginal epithelium ↓ hypertrophy and loosen from connective tissues ↓ prepare for great distention at birth  Presumptive sign  Chadwick’s sign  color of vaginal wall changes from normal light pink to deep violet  ↑ vascularity and ↑ circulation  Probable sign  VAGINAL CHANGES  Vaginal secretions  pH fall from >7 to 4 or 5 because of the action of Lactobacillus acidophilus  vagina resistant to bacterial invasion for the length of pregnancy  Candida albicans favors this environment * Mother: Candidal infection * itching and burning sensation, creamcheese - like discharge *Newborn: Candida infection: thrush / oral monilia  OVARIAN CHANGES PLACENTA later in pregnancy ↓ pituitary gland = X production of FSH and LH ↓ X ovulation  BREAST CHANGES  6th week: feelings of fullness, tingling, tenderness  ↑stimulation of breast tissue (↑ estrogen level) ↑ Breast size  hyperplasia of mammary alveoli and fat deposits  Areola: darkens, diameter increases (1.5 in to 2-3in)  Blue veins more prominent over surface of breasts (↑ vascularity)  BREAST CHANGES Montgomery’s tubercles = secretions keeps nipple supple / elastic = helps prevent nipples from cracking and drying during lactation 16th week: colostrum can be expelled = thin, watery, high-protein fluid – precursor of breast milk  INTEGUMENTARY SYSTEM  Striae gravidarum  pink or reddish streaks on the sides of the abdominal wall and thighs Stretching ↓ rupture and atrophy of connective layers of the skin ↓ lighten to a silvery-white color ↓ striae albicantes or atrophicae Striae gravidarum Striae atrophicae  INTEGUMENTARY SYSTEM  28th week: Umbilicus has turned inside out, protruding as a round bump at the center of the abdominal wall  Linea nigra  narrow, brown line from umbilicus to symphysis pubis  Melasma / Chloasma / Mask of Pregnancy  darkened areas on face, cheeks and across the nose  melanocyte-stimulating hormone – pituitary mask of pregnancy/chloasma/melasma  INTEGUMENTARY SYSTEM  Vascular spiders (telangiectases)  small, fiery-red branching spots on thighs  ↑ level of estrogen ↑ Perspiration Active / increase activity of sweat glands  Palmar erythema  redness and itching on hands  ↑ level of estrogen  RESPIRATORY SYSTEM  Congestion or stuffiness of the nasopharynx  ↑ estrogen level  Allergy/cold  OTC cold medications/ antihistamines to relieve congestion  Displaced diaphragm Uterine enlargement ↓ crowding of the chest cavity ↓ acute sensation of SOB late in pregnancy ↓ lightening relieves the pressure  4 cm upward  TEMPERATURE CHANGES ↑ Temperature early in pregnancy  99.°6 F (oral)  ↑ progesterone (Corpus luteum)  related to nasal congestion (sure sign of cold)  16thweek: decreased temperature placenta will take over in the production of progesterone  CARDIOVASCULAR SYSTEM ↑ Blood volume (30% - 50%)  adequate exchange of nutrients in the placenta  to compensate for blood loss during childbirth  NSD  CS *Pseudoanemia - ↑ plasma volume increases / RBC production  CARDIOVASCULAR SYSTEM  ↑ Iron requirement (800ug)  fetus to grow (350-400 ug)  ↑ circulating RBC (400 ug)  Iron supplementation may be prescribed to prevent true anemia  ↑ Folic acid  megalohemoglobinemia  ↑ risk for neural tube disorders in fetus  spinach, asparagus, legumes  ↑ Cardiac output (25% - 50%)  HR increases by 10bpm  Palpitations are not uncommon  Edema and varicosities of the vulva, rectum, and legs  Impaired blood flow to lower extremities  Pressure of the expanding uterus on veins and arteries  CARDIOVASCULAR SYSTEM  Supine Hypotension syndrome Supine ↓ presses the vena cava against the vertebrae ↓ obstruction of blood flow from lower extremities ↓ ↓ blood return to the heart ↓ ↓ cardiac output and hypotension ↓ lightheadedness, faintness, palpitations  MOTHER: Hypotension  FETUS: Hypoxia  Management: Left lateral position (↑ blood flow on vena cava)  2nd Trimester: ↓ BP (↓ peripheral resistance and placental expansion)  CARDIOVASCULAR SYSTEM  ↑ circulating fibrinogen (50%) = ↑ estrogen  ↑ factors VII, VIII, IX and X + platelet count = safeguard against major bleeding placenta be dislodged ↓ uterine arteries or veins be opened  ↑ WBC = protective mechanism = reflection of woman’s increased total blood volume  ↓ total protein level = used by fetus + hypervolemia = common ankle edema and feet edema of pregnancy  GASTROINTESTINAL SYSTEM Midpoint of pregnancy ↓ ↑ uterine pressure ↓ stomach and intestines are pushed back and on the sides of the abdomen ↓ slow gastric and intestinal peristalsis and emptying time of stomach Relaxin (ovaries) Progesterone ↓ ↑ heartburn, constipation, flatulence, hemorrhoids  GASTROINTESTINAL SYSTEM  Nausea and Vomiting “morning sickness”  early in the morning, on rising, fatigued during the day  50% of women  1st sensations a woman may experience with pregnancy  ↑ women who smoke cigarettes  ↑ HCG, progesterone, and estrogen / ↓ glucose (growing fetus) Upward displacement of the stomach (uterus) + relaxed cardioesophageal sphincter = relaxin (ovary) ↓ reflux of stomach contents into the esophagus (Heartburn)  Acupuncture, drinking ginger or peppermint tea  GASTROINTESTINAL SYSTEM  Hemorrhoids = pressure from uterus on veins returning from lower extremities  Hypertrophy at gums and bleeding of gingival tissue  Hyperptyalism  ↑ saliva formation  ↑ estrogen level  may lead to tooth decay if pH is lower than normal  URINARY SYSTEM  Fluid retention  7.5L (total increase in body water)  aids to provide sufficient blood volume for effective placental exchange  serves as ready source of nutrients to the fetus through placental perfusion  ↑ Estrogen and Progesterone ↑ Urine Output (60% - 80%)  1st tri: ↑ urination (pressure on the bladder by the uterus)  2nd tri: uterus rises out of the pelvis and relieves pressure on bladder  3rd tri: ↑ frequency of urination (lightening)  3rd trimester 2nd trimester 1st trimester  RENAL FUNCTION  Woman’s kidneys must excrete waste products from her body and growing fetus = able to excrete additional fluid  ↑ diameter of ureters and ↑ bladder capacity (1500 ml) = ↑ Progesterone  Infections (UTI) = ascend kidney infection = preterm labor  SKELETAL SYSTEM  ↑ needs for calcium and phosphorus  development of fetal skeleton  Softening of pelvic ligaments and joints  facilitate passage of the fetus  relaxin and placental Progesterone  Stand straighter and taller than usual  “pride of pregnancy”  shoulders back and the abdomen forward  changes center of gravity and makes ambulation easy  creates lordosis (forward curvature of the lumbar spine)  Lordotic position: leads to backache  ENDOCRINE SYSTEM  Addition of placenta as a separate endocrine organ  Estrogen  Breast and uterine enlargement, palmar erythema  Progesterone  Maintains endometrium, inhibits uterine contractility, aids in development of breast  hPL  Antagonist to insulin which allows glucose to be available  Relaxin  Inhibits uterine activity, softens cervix and collagen in the lower spine  Prostaglandins  Affects smooth muscle contractility that initiates labor at term  ENDOCRINE SYSTEM  Thyroid gland enlarges for increased basal body metabolic rate (20%)  Protein-bound iodine, butanol-extractable iodine and thyroxine are increased to prevent goiter (tachycardia, palpitations, increased perspiration)  Parathyroid glands  ↑ size for the metabolism of calcium (fetal growth) o Adrenal glands o ↑ activity = ↑ levels of corticosteroids & aldosterone (to reduce the possibility of the woman’s body rejecting the foreign protein of the fetus) o Prolactin (lactation) o Oxytocin (labor)  IMMUNE SYSTEM  Immunologic competency decrease = X rejecting fetus  Decreased production of IgG (Immunoglobulin G) = more prone to infection  Increased WBC = counteracts low IgG levels  WEIGHT  an increase of about 25 to 35lbs throughout pregnancy: fetus ----- 7.5 placenta ----- 1.5 amniotic fluid ----- 2 increased wt of uterus ----- 2.5 increased blood volume ----- 4 increased breast wt ----- 1.5 to 3 additional fluid ----- 4 body fat ----- 7  SIGNS OF PREGNANCY  Presumptive signs  Least indicators of pregnancy because they could easily indicate other conditions  Largely subjective  Experienced by the woman but cannot be documented by the examiner  Probable signs  Can be documented by the examiner  Although more reliable than presumptive signs, they are not still positive or true diagnostic findings  Positive Signs  Fetal heart rate separate from the mother’s , fetal movement felt by the examiner, fetal visualization by UTZ  PRESUMPTIVE SIGNS  Breast changes (2nd week)  Nausea & vomiting (2nd week)  Amenorrhea (2nd week)  Frequent urination (3rd week)  Fatigue (12th week)  Uterine enlargement (12th week)  Quickening (18th week)  Linea nigra, melasma, striae gravidarum (24th week)  PROBABLE FINDINGS  Serum laboratory tests (1st week) = HCG  Chadwick’s sign (6th week)  Goodell’s sign (6th week)  Hegar’s sign (6th week)  Sonographic evidence of gestational sac (6th week)  Ballottement (16th week)  Braxton Hicks contractions (20th week)  Fetal outline felt by the examiner (20th week)  POSITIVE FINDINGS  Audible fetal heart sounds(10-12th week) = Doppler = 18-20 weeks = stethoscope = 120-160 bpm = Fetal back  Fetal movement felt by the examiner (20-24th week) = X extremely obese  Visualization of fetus by UTZ (4-6-8th week) = Site of implantation, multiple pregnancy exists THANK YOU SO MUCH!!!