Reproductive and Sexual Health.pdf

Reproductive and Sexual Health Nursing Role in Reproductive and Sexual Health Terminologies Procreation...

Reproductive and Sexual Health Nursing Role in Reproductive and Sexual Health Terminologies Procreation ▪ Andrology - study of male reproductive - Process that permits two living beings to organs produce a third one that is different from ▪ Aspermia - absence of sperm each of them ▪ FSH - Follicle Stimulating hormone - During procreation in humans, each parent ▪ GnRH - Gonadotropin-releasing hormone transmits to the child one of the two copies ▪ Gynecology - study of female reproductive of his or her genetic material, located on the organ parent’s 23 pairs of chromosomes ▪ LH - Luteinizing hormone - The transfer is made by the parent’s ▪ Menarche - first menstruation gametes, reproductive cells that contain ▪ Menses’ - period of mild hemorrhage only 23 chromosomes as a result of a during which part of the endometrium is special kind of cell division: meiosis sloughed and expelled from the uterus Theories of Procreation ▪ Spermatogenesis - formation of sperm In the foundational texts of the three cells monotheistic religions that trace their roots to Functions of the Reproductive System Abraham, she said, procreation is imagined as Male the father planting the "seed" of a child in the - Production of sperm cells "soil" of the mother's womb. "The mother is - Sustaining and transferring the sperm cells understood to nurture the seed, but the seed itself to the female was created by and belongs to the father. In that - Production of male sex hormones conception of procreation, the father and child are Female related in a very different way from mother and - Production of female sex cells child." - Reception of sperm cells from the male - Inherited or genetic disorders are disorders - Nurturing the development of and providing that can be passed from one generation to nourishment for the new individual the next - Production of female sex hormone - Result from some disorder in gene or Female Reproductive System (External) chromosome structure Genetics – the study of the ways such disorders occur Nature of Inheritance Genes - basic units of heredity that determine both the physical and cognitive characteristics of people Chromosomes - 46 chromosomes (44 autosomes and 2 sex chromosomes) Phenotype - outward appearance or the expression of the genes Genotype - actual gene composition Genome - complete set of genes present (46XX, 45XY)  Mons Veneris - pad of adipose tissue located over the symphysis pubis, the pubic bone - covered by a triangle, coarse, curly hair, - to protect the junction of the pubic bone from trauma Labia Minora - immediately posterior to mons veneris - 2 hairless folds of connective tissues - pink in color, abundant with sebaceous glands Labia Majora - 2 folds of tissue, fused anteriorly but separated posteriorly - composed of loosed connective tissue covered by epithelium and pubic hair Vestibule - Flattened smooth surface inside the labia Clitoris - A small approx. 1-2cmrounded organ of erectile tissue at the forward junction of the minora - Center of sexual arousal among woman Mons pubis/Veneris Two Skene glands (paraurethral) - located on each side of the urinary meatus Bartholin glands (vulvovaginal) - located on each side of the of the vaginal opening - secretions from the glands help to ▪ Tanner scale tool lubricate external genitalia during coitus - used to determine sexual maturity rating Fourchette ▪ Stage 1 - Posterior, tapers posteriorly of the labia - Pre-adolescence. No pubic hair. Fine minora – sensitive to manipulation, torn body hair only during delivery. ▪ Stage 2 - site of episiotomy to enlarge the vaginal - Occurs between ages 11 and 12 – opening sparse, long, slightly pigmented & curly Hymen hair at pubis symphysis - tough but elastic semicircle that covers the ▪ Stage 3 opening of the vagina - occurs between ages 12 and 13 – darker - often torn during & curlier at labia ▪ Stage 4 - occurs between ages 13 and 14, hair assumes the normal appearance of an adult but is not so thick and does not appear to be the inner aspect of the upper thigh. ▪ Stage 5 - sexual maturity – normal adult appears inner aspect of the upper thigh  Fallopian Tubes: - arise from each upper corner of the uterine body - approx. 10 cm long in a mature woman - Smooth hollow tunnel ▪ Functions: - convey the ovum from the ovaries to the uterus - provide a place for fertilization of the ovum by sperm ▪ 4 significant segments/parts of the Fallopian Tubes: 1. Interstitial - site of ectopic pregnancy – the most Female Reproductive System (Internal) dangerous Vagina - most proximal division, about 1cm - female organ of copulation, the long, lumen is 1mm diameter passageway of men & fetus, 3 – 4inches 2. Isthmus or 8 – 10 cm long, dilated canal - site of sterilization – bilateral tubal Rugae ligation - permits stretching without tearing - distal portion, about 2 cm in length Three parts of the uterus - part of the tube that is ▪ corpus/body - cut or sealed during tubal ligation or ▪ Isthmus tubal sterilization ▪ Cervix 3. Ampulla - outer 3rd or 2nd half, site of Ovaries fertilization ▪ Size: 3cm long x 2cm in diameter and 1.5 - third and the longest portion of the cm thick tube, about 5cm long ▪ Shape: Almond - tube where fertilization of an ovum ▪ Color: Grayish White and appear pitted, occurs with minute indentations on the surface 4. Infundibulum - distal part of FT, trumpet or funnel- Note: Cannot be located by palpations, only if an shaped, swollen at ovulation abnormality exists - most distal part of the tube, about 2 ▪ Functions: cm long, funnel shape and covered - to produce, mature, and discharge ova by fimbria a small hair that guides – the egg cells the ovum into the fallopian tube - Further in the process of producing ova, ovaries produce estrogen and progesterone - Initiate and regulate the menstrual cycle ▪ Additional information about ovaries - If the ovaries are removed before puberty or become nonfunctional it will prevent the maturation and maintenance of secondary sex characteristics - Pubic hair distribution will assume a more male-than-female pattern  Uterus - Consist of 2 layers of cells important - is a hollow, thick-walled muscular organ. It for menstrual function varies in size, shape, and weight. - Basal layer uninfluenced by ▪ Size: With maturity, size is about 5 to 7cm hormones long, 5cm wide - Glandular layer influenced by ▪ Shape: non-pregnant – pear-shaped; estrogen and progesterone, pregnant – ovoid; Childhood – olive capable of supporting the shape pregnancy ▪ Weight: Non-pregnant – 60g; pregnant - If pregnancy does not occur this – 1,000g layer is shed as the menstrual flow ▪ Pregnant/ Involution of uterus: o Myometrium o 4th stage of labor – 1000 g - middle layer of muscle fibers o 2nd weeks after delivery – 500 g - constrict the fallopian tube at the o 3rd weeks after delivery – 300 g point they enter the fundus o 5-6th weeks after delivery – 80 g preventing regurgitation of ▪ Functions: menstrual blood into the tubes - Receive the ovum from the fallopian - Holds the internal cervical os closed tube during pregnancy to prevent - Provide a place for implantation and preterm birth nourishment o Perimetrium - Furnish protection from a growing fetus - outermost layer of the uterus - Expel the fetus from the woman's body - Add further strength and support to the organ Note: after pregnancy, it never returns to its non- pregnant state, size approx. 9cm long, 6cm wide, 3cm thick, and 80g weight ▪ 3 divisions of Uterus 1. Body of uterus or corpus - uppermost part that expands to contain the growing fetus o Fundus - palpated to determine the amount of uterine growth, - measure the force of uterine contractions - assess that the uterus is returning to its nonpregnant state 2. Isthmus - short segment between the body and the cervix - portion where the incision is made when the fetus is born through CS 3. Cervix - lowest portion, about one-third of the total uterine size, about 2-5cm long ▪ Layers of Uterus (E-M-P) o Endometrium - An inner layer of mucous membrane  Reproductive System Testes Androgen-p81 - 2 ovoid glands, 2-3 cm wide, rest in the - hormone responsible for muscular scrotum development, physical growth - in the fetus it forms in the pelvic cavity and - in males it is produced by the adrenal descends late intrauterine about 34-38th cortex and testes weeks - in females the adrenal cortex and ovaries - cryptorchidism undescended testes may Role of Estrogen not produce viable sperm and have a 4 to - When triggered at puberty by FSH, ovarian 7 times increase in the rate of testicular follicles in females begin to excrete high cancer levels of estrogen Penis - increase influences the development of the - Composed of 3 cylindrical masses of uterus, fallopian tubes, vagina, hair pattern, erectile tissue in the penis shaft and breast development - serve both as an outlet for the urinary and - closes the epiphyses of long bones in reproductive tract in men females in the same way testosterone - nitric oxide is released from the closes the growth plates in boys endothelium of blood vessels during ▪ Thelarche excitement - beginning of breast development which Male Reproductive System (Internal) usually starts 1 to 2 years before Epididymis menstruation - a seminiferous tubule of each testis leads to a tightly coiled tube - responsible for conducting sperm from the tubule to the vas deferens - 20 ft long, tightly coiled Vas Deferens - a hollow tube surrounded by arteries and veins and protected by a thick fibrous coating ▪ Spermatic cord - carries sperm from epididymis through the inguinal canal into the abdominal cavity, where it ends at the seminal vesicles and ejaculatory ducts below the bladder Seminal vesicles - 2 convoluted pouches that lie along the Male Reproductive System (External) lower portion of the bladder and empty into Scrotum the urethra by ejaculatory ducts - rugate, skin-covered, muscular pouch Prostate gland hanging below the pendulous penis, with a - Chestnut-sized gland that lies just below medial septum dividing into two sacs, each the bladder and allows the urethra to pass of which contains a testes through the center of it like the hole in the ▪ Functions: doughnut - support the testes - Secrete a thin, alkaline fluid, which, when - help regulate the temperature of the added to the secretion from seminal sperm vesicles - in cold weather scrotal muscle contracts - protects sperm by increasing the natural to bring the testes closer to the body pH level of the urethra - in hot weather muscle relaxes, allowing testes to fall away from the body  Bulbourethral glands The Process of Spermatogenesis - 2 bulbourethral or Cowper’s glands lie beside the prostate gland and empty by short ducts into the urethra - Supply one more source of alkaline fluid to help ensure the safe passage of spermatozoa - Semen derived from prostate gland (60%), seminal vesicles (30%), epididymis (5%), bulbourethral glands (5%) Urethra - Hollow tube leading from the base of the bladder, which after passing thru the prostate gland, continues to the outside thru the shaft and glans of the penis - about 8 in. (18 to 20 cm) long Luteinizing hormone (LH) - produced and released in the anterior pituitary gland. - This hormone is considered a gonadotrophic hormone because of its role in controlling the function of ovaries in females and testes in males, which are known as the gonads. What does the luteinizing hormone do? (Women) - In women, the hormone stimulates the ovaries to produce estradiol - Two weeks into a woman's cycle, a surge in luteinizing hormone causes the ovaries to release an egg during ovulation. - If fertilization occurs, luteinizing hormone will stimulate the corpus luteum, which produces progesterone to sustain the pregnancy. (Men) - For men, luteinizing hormone stimulates the production of testosterone from Leydig cells in the testes. - Testosterone, in turn, stimulates sperm production and helps accentuate male characteristics — like a deep voice or growth of facial hair.  Male and Female Homologues than 1 hr. is heavy Male Female bleeding Penile glans Clitoral glans Color of menstrual Dark red; a Penile shaft Clitoral shaft flow combination of blood, Testes Ovaries mucus, and Prostate Skene’s glands endometrial cells Cowper’s Glands Bartholin’s glands Odor Similar to marigold Scrotum Labia Majora Related terminologies Physiology of Menstrual Cycle ▪ Menarche Menstruation ▪ Menopause - episodic uterine bleeding in response to ▪ Dysmenorrhea cyclic hormonal changes. ▪ Metrorrhagia - It is a process that allows for conception ▪ Menorrhagia and implantation of new life ▪ Amenorrhea - begins at puberty and ends at menopause Characteristics of Normal Menstrual Cycle Characteristics Description Beginning Average age at onset, (Menarche) 12.4 yrs. average range, 917 years Interval between Average, 28 days; the cycles cycle of 23-35 days is not unusual Duration of Average flow, 4-6 menstrual flow days, range of 2-9 days nor abnormal Amount of menstrual Difficult to estimate; flow average 30- 80ml/menstrual period; saturating a pad or tampon in less  First Phase Proliferative phase - can be estimated by subtracting 14 days - Immediately after a menstrual flow (4 or 5 from the length of the menstrual cycle days of the cycle), the endometrium or the - period wherein estrogen is high and lining of the uterus is very thin. As the ovary progesterone is low begins to produce estrogen, - Thickness of the endometrium increases as much as eightfold from day 5 to 14 Second Phase Secretory/Luteal/pregestational/pre- menstrual phase (after ovulation). - formation of progesterone causes the glands of the uterine endometrium to become cock-screw or twisted - appearance of rich, spongy velvet Third Phase (Ischemic phase) - if fertilization does not occur, the corpus luteum in the ovary begins to regress after 8-10 days, production of progesterone decreases. - With the withdrawal of the progesterone, the endometrium of the uterus begins to degenerate (24 or 25 cycles), capillaries rupture with minute hemorrhage, and Spinnbarkeit test endometrium sloughs off - A cervical mucus is stretched in a long Fourth Phase (Manses’) strand as demonstrated by a high level of - composed of a mixture of blood from the estrogen ruptured capillaries, mucin, fragments of Mittelschmerz endometrial tissue, and microscopic, - pain in the pelvis that some women have atrophied, and unfertilized ovum during ovulation - Menstrual flow is about 30 to 80ml of blood Cervical Changes - At the beginning of each cycle, when estrogen is LOW cervical mucus is thick and scant, sperm survival is POOR - During ovulation estrogen level is HIGH, and cervical mucus becomes thin, stretchy (spinnnbarkeit), and copious therefore sperm penetration and survival are both EXCELLENT - During ovulation the body of the cervix is softer, and Os is slightly open Ovulation Indicators - slight increase in basal body temperature, spinnbarkeit, mittelschmerz - women are most fertile during this period The uterus is prepared for implantation of Process of Conception the developing blastocysts by day 21 Estrogen stimulates proliferation of the endometrium, and progesterone causes thickening of the endometrium. Decreased progesterone causes menses FSH initiates the development of the follicle Estrogen produced by the follicles stimulates GnRH, FSH, and LH secretion, and FSH and LH stimulate more estrogen secretion. This positive- feedback mechanism causes FSH and Fertilization (Video link) LH levels to increase near the time of ovulation ▪ Pregnancy starts with the meeting of LH stimulates ovulation and formation of the sperm and egg corpus luteum ▪ Sperm are made in testicles, and eggs live Estrogen and Progesterone inhibit LH and FSH in ovaries secretion following ovulation ▪ Hormones control the menstrual cycle and If fertilization does not occur, progesterone cause eggs to mature secretion by the corpus luteum decreases and ▪ Ovulation occurs when a mature egg menses begin leaves the ovary Mittelschmerz – slight abdominal pain on L or ▪ If semen enters the vagina, sperm can RQ of the abdomen, marks ovulation day swim up and search for an egg ▪ Fertilization happens when a sperm cell joins with an egg ▪ The fertilized egg moves towards the uterus and implants into the uterine lining ▪ Pregnancy hormones are produced when the ball of cells implants ▪ Without fertilization or implantation, the uterine lining is shed during menstruation  Sperm - Male reproductive cell - Produced in the testes particularly seminiferous tubules - Consisting of head or nucleus, middle piece (neck) and tail - About 0.05 mm in length - Carried 23 chromosomes o 22 autosomes o 1 sex chromosome - Carries 2 types of sex chromosomes, X and Y which when united with the X chromosome determine the sex of the child. - XY is male, XX is female - 33-46 million sperm/ml or 50 million/ejaculation - 2.5ml of seminal fluid/ejaculation - Contains 50-200million spermatozoa/ml or an average of 400 million sperm/ ejaculation Ovum - Female reproductive cell - Found in ovary - A round cell, about 0.1 mm in diameter If mature - Appears like a clear water blister 0.25 – 0.5 across - approximately the size of a printed period - Carried 23 chromosomes o 22 autosomes o 1 sex chromosome - Carries X chromosomes Gamete - Is a sex cell ovum or spermatozoon that has undergone maturation and is ready for fertilization Fertilization: The beginning of pregnancy - Heteropaternal Superfecundation 175 - means the fertilization of more than one Conception, Impregnation, or Fecundation egg during the same cycle. That is to say - The union of sperm and ovum occurs in the that two eggs are fertilized by sperm from outer third of the fallopian tube, the ampullar different men. portion - Usually only one ovum reaches maturity a Stages of fetal development month Pre-embryonic First 2 weeks - Fertilization must occur fairly quickly because beginning fertilization the ovum is capable of fertilization for only 24 Embryonic Weeks 3 through hours, 48 hours at the most week 8 - The life span of spermatozoon is about 48-72 Fetal From 8 weeks through hours birth - The total critical time during fertilization may - Hyaluronidase occur is about 72 hours (48 hours before - Penetration ovulation plus 24 hours afterward) - Zygote Conditions Necessary for Fertilization 1. Maturity of the egg and sperm. Terms used to describe fetal growth 2. Ability of the sperm to reach the ovum 3. Ability of the sperm to penetrate the zona Name Time pellucida and cell membrane Ovum from ovulation to 4. Timing of deposit of sperm fertilization a) The lifetime of the ovum is 24 hours Zygote from fertilization to b) The lifetime of sperm is 72 hours implantation c) The ideal time for fertilization is 48 hours Embryo from implantation to 5 before to 24 hours after ovulation – 8 weeks 5. Climate of the female genital tract Fetus from 5 – 8 weeks until a) vaginal and cervical secretions are less term acidic during ovulation Conceptus Developing embryo b) cervical secretions are thinner during and placental ovulation structures throughout pregnancy Implantation Age of viability The earliest age at - contact between the growing structure and the which fetuses survive uterine endometrium if they are born is - Occurs in the 8th to 10th day after fertilization generally accepted as - occurs high in the uterus on the posterior 20-24 weeks or at the surface point a fetus weighs - if implantation is low the growing placenta may more than 500-600g occlude the cervix and make the birth difficult (placenta previa) Process of Fertilization - Ovulation - Ovum o Zona pellucida o Corona radiata - Semen - Spermatozoa - Capacitation  Process of Implantation - Zygote Embryonic and fetal structures - Morula - Blastocyst Decidua or Uterine Chorionic villi o Apposition lining o Adhesion Placenta Fetal Membranes o Invasion Amniotic Fluid Umbilical Cord - Trophoblast cells - Embryoblast cells Decidua - Once fertilization is complete, the zygote ▪ 3 divisions migrates for 3 to 4 days to reach the body o Decidua Basalis of the uterus, this time mitotic cell - part of the endometrium lying directly division or cleavage begins. The first under the embryo and where cleavage occurs at about 24 hours. trophoblast cells are establishing - As the zygote reaches the uterus it consists communication with maternal blood of 16 to 50 cells. Its bumpy outward vessels. appearance is called the morula. o Decidua capsularis - stretches or encapsulates the surface of the trophoblast. o Decidua vera - the remaining portion of the uterine lining - HCG causes the uterine endometrium to continue to grow in thickness and vascularity instead of sloughing off as in the usual menstrual cycle, the endometrium is now termed decidua because it will be discarded after birth.  Chorionic Villi o 1 – slightly mature - 11th or 12th day o 2 – moderately mature - miniature villi or probing “fingers” reach out o 3 – placental maturity from the single layer of cells into the uterine endometrium ▪ 2 layers of Chorionic Villi o Syncytiotrophoblast or Syncytial layer - outer layer - responsible for the production of HCG Somatomammotropin (human placental lactogen) Estrogen progesterone ▪ Cytotrophoblast or Langhan’s layer - Middle layer - protects the growing embryo and fetus from infectious organisms such as spirochete of syphilis - Disappear between 20th &24th week - Appears to have little protection against ▪ Functions of Placenta viral disease - Main source of nourishment - Provides oxygen and removes CO2 from fetal system - Maintains fetal fluid and electrolyte, acid-base balance. - Acts as a barrier to some particles and organisms - Provides maternal immunoglobulin G that gives the fetus passive immunity to certain diseases for the first few months after birth - Exchange takes place between mother and fetus through diffusion ▪ Respiratory System - beginning of lung function after the birth of the baby. Simple diffusion Placenta (Pancake) ▪ GIT - develops by the 3rd week - transport center, glucose transport is - formed by the union of chorionic villi and facilitated, diffusion is more rapid from decidua basalis higher to lower. If the mom is - 30 cotyledons hypoglycemic, the fetus hypoglycemic - weighs 400 - 600 grams. ▪ Excretory System - The rate of uteroplacental blood flow in - artery - carries waste products. The liver of pregnancy increase about 50ml /minute at the mom detoxifies the fetus. 10 weeks to 500 - 600ml/minute at term ▪ Circulating system - 1/6 the weight of the baby - achieved by selective osmosis - calcium -deposited in the placenta which signifies maturity - placental grading – rating/grade o 0 – immature  ▪ Endocrine function -Promotes mammary gland growth in o HCG preparation for lactation in the mother, - first placental hormone produced regulates maternal glucose, protein, and during pregnancy fat levels so that adequate amounts are - Can be found in maternal blood and always available to the fetus urine after implantation occurred 3. Estrogen (about 100th day of pregnancy) - contributed to the mother’s mammary o Estrogen gland development and stimulates the - “Hormone of women” uterus to grow. The precursor of - contributes to the mother’s mammary estrogen is a compound produced by gland development in preparation for the fetal adrenal gland and liver lactation - When the fetus is distressed, the - stimulates uterine growth production of the fetal compound is o Progesterone decreased, estrogen cannot be - “Hormone that maintains pregnancy” synthesized and the level of estriol in - maintains the endometrial lining of maternal estrogen will then be the uterus during pregnancy decreased. - reduce contractility of the uterus 4. Progesterone during pregnancy, which prevents - maintains the endometrial lining of the premature labor uterus - responsible for the reduced contractility of the uterine musculature during pregnancy which prevents labor. The reduction in contractility is produced by a change in electrolytes such as potassium and calcium which decreases the contraction potential of the uterus Fetal Membrane - membranes that surround the fetus and what give the placenta the shiny appearance ▪ Chorionic membrane - Outermost fetal membrane Placental Hormones 1. Human Chorionic Gonadotrophin (HCG) Amniotic membrane - detected in urine and maternal blood ▪ 2 layers shortly after implantation. It stimulates o Chorion (CO-OUT) the corpus luteum to maintain - Outermost part endometrium and is a basis test for o Amnion (AM-IN) pregnancy - Innermost part - On the 8th week of pregnancy, the placenta begins to produce Note: the 2 fused as the pregnancy progressed progesterone, so the corpus luteum is and appeared as a single sac and no nerve supply no longer needed and the production of - offers support to amniotic fluid HCG decreases. The mother’s serum - produce the amniotic fluid will be completely negative for HCG - No nerve supply within 1 - 2 weeks after delivery. - produce phospholipids that initiate the 2. Human Chorionic Somatomammotropin formation of prostaglandins which may be (Human Placental Lactogen) the trigger to initiate labor - produced on the 6th week of pregnancy and increased in amount to a peak level at term. ▪ Amniotic Fluid ▪ Function of amniotic fluid - forms within the amniotic cavity and - To shield the fetus against pressure or a surrounds the embryo blow to the mother’s abdomen - 800ml - 1200ml - protects the fetus from changes in - contains fetal urine, lanugo from fetal temperature skin, epithelial cells, and subaqueous - aids muscular development as it allows materials the fetus freedom to move - pH = 7.2 - protects the umbilical cord from - specific gravity 1.005 - 1.025 pressure, protecting fetal oxygenation - oligohydramnios – less than 300ml Remember: Even if amniotic fluid ruptures before - polyhydramnios/hydramnios – more birth and the bulk of it is lost, some will always than 2000ml surround the fetus in utero because new fluid is - Never become stagnant constantly produced - The fetus continually swallowed the fluid - Absorbed from the fetal intestine into the fetal bloodstream - Goes to the umbilical arteries and the placenta and is exchanged across the placenta to the mother’s bloodstream - appropriate amount ensures adequate kidney function Umbilical Cord - formed from amnion and chorion - initiate circulatory communication - Transport oxygen and nutrients to the fetus from the placenta - Returns waste products from the fetus to the placenta ▪ A-V-A - Vein carrying blood from placenta villi to the fetus - Arteries carrying blood from the fetus back to the placental villi - Single veins and arteries are found with accompanying chromosomal and congenital disorders, particularly kidney and heart - About 53cm (21in.) in length, about 2 cm thick - the rate of blood flow through an umbilical cord is 350ml/min at term - 1 vein and 2 arteries (AVA) - Wharton’s jelly  ▪ Wharton’s jelly End of 4th Gestational Week - gives the cord body and protects the - Length: 0.75 to 1 cm vein and arteries from pressure - Weight: 400 mg - blood can be withdrawn from the - The spinal cord is formed and fused at the umbilical vein or transfused into the vein midpoint during intrauterine life for fetal - Head is large in proportion and represents assessment and treatment about 1/3 of the entire structure - smooth muscle is abundant in the - The rudimentary heart appears as a arteries of the cord and the constriction prominent bulge on the anterior surface of these muscles after birth contributes - Arms and legs are budlike structures to hemostasis and helps prevent - Rudimentary eyes, ears, and nose are hemorrhage in the newborn discernible End of 8th Gestational Week - Length: 2.5 cm (1inch) - Weight: 20 gm - Organogenesis is completed - The heart, with septum and valves, is beating rhythmically - Facial features are discernible - Arms and legs have developed - External genitalia are present, but sex is not distinguishable by simple observation Schultze presentation-Fetal Side - The primitive tail is regressing - The abdomen appears large because the fetal intestine is growing rapidly - Sonogram shows a gestational sac, diagnostic of pregnancy End of 12th Gestational Week - Length: 7 to 8 cm - Weight: 45 gms - Nail beds are forming on fingers and toes - Spontaneous movements are possible although they are usually too faint to be felt by the mother - Some reflexes such as the Babinski reflex are present - Bone ossification centers are forming - Tooth buds are present - Sex is distinguishable by outward appearance - Kidney secretion has begun although urine may not be evident in amniotic fluid Milestone of fetal growth and development - Heartbeat is audible through Doppler - Both ovulation and gestational age are technology reported in LUNAR months (4 weeks period) or TRIMESTER (3 months period End of 16th Gestational Week - In LUNAR months, a total pregnancy is 10 - Length: 10 to 17 cm months (40 weeks or 280 days) - Weight: 55 to 120 gms - A fetus grows in utero for 9.5 lunar months or - Fetal heart sounds are audible with an 3 full trimester (38 weeks or 266 days) ordinary stethoscope  - Lanugo is well-formed End of 32nd Gestational Week - Liver and pancreas are functioning - The fetus responds by movement to - Fetus actively swallows amniotic fluid sounds outside the mother’s body demonstrating an intact but uncoordinated - Length: 38 to 43 cm swallowing reflex - Weight: 1600 gms - urine is present in the amniotic fluid - Subcutaneous fat begins to be deposited - Sex can be determined by - Fingernails grow to reach the end of the ultrasonography fingertips - Active Moro reflex is present End of 20th Gestational Week - Birth position may be assumed - Length: 25 cm - Iron stores are beginning to be developed - Weight: 223 gms - Spontaneous fetal movements can be End of 36nd Gestational Week sensed by the mother - Body stores of glycogen, iron, - Antibody production is possible carbohydrate, and calcium are deposited - Hair forms, extending to include eyebrows - Length: 42 to 48 cm and hair on the head - Weight: 1800 to 2700 gms - Meconium is present in the upper intestine - An additional amount of subcutaneous fat - Brown fat begins to be formed behind the is deposited kidneys, sternum, and posterior neck - The sole of the foot has only one or two - Vernix caseosa begins to form behind the creases kidney, sternum, and posterior neck - Amount of Lanugo begins to diminish - Definite sleeping and activity patterns are - Most babies turn into a vertex or head- distinguishable down presentation during this month End of 24th Gestational Week End of 40th Gestational Week - Length: 28 to 36 cm - Fetal hemoglobin begins its conversion to - Weight: 550 gms adult hemoglobin - Meconium is present as far as the rectum - Length: 48 to 52 cm - Passive antibody transfer from mother to - Weight: 3000gms (7 to 7.5 lbs) fetus probably begins as early as the 20th - Fetus kicks actively, hard enough to cause week of gestation, certainly for the 24th the mother considerable discomfort week - Vernix caseosa starts to decrease after 37 - Active production of lung surfactant begins weeks and is apparent in the creases than - Eyebrows and eyelashes are well defined the covering of the body as the infant - Eyelids previously fused since the 12th approaches 40 weeks week, are now open - Fingernails extend over the fingertips - Pupils are capable of reacting to light - Creases on the sole of the feet cover at - Hearing can be demonstrated by response least 2/3 of the surface to sudden sound End of 28th Gestational Week - Length: 35 to 38 cm - Weight: 1200 gms - Lung alveoli begin to mature, and surfactants can be demonstrated in amniotic fluid - Testes begin to descend into the scrotal sac from the lower abdominal cavity - The blood vessels of the retina are thin and extremely susceptible to damage from high oxygen concentration