Title WK4 - Fetal Development & Milestones.pdf ✅

J.A.K.E 1 of 6 Bachelor of Science in Nursing 2YA NCMA217 LEC: FETAL DEVELOPMENT & MILESTONES Discussed by: Prof. Francis Vasquez Prof. Jhal Espinosa FETAL DEVELOPMENT - 38- 40 weeks - 3 stages: 1) Pre-embryonic development/stage – 1st 2 weeks after fertilization. (1-14 days) 2) Embryonic development/stage – 2 weeks to 2 months/ week 3-8 (15th day – 2 mos.) 3) Fetal development/stage – 2 months to birth (week 8- birth) - Ovum – from ovulation until fertilization - Zygote – from fertilization until implantation - Embryo – from implantation until 5-8 weeks of life - Fetus – from 5-8 weeks until term. - Organogenesis – formation of organ, begins 1st 2 months of pregnancy. Self-medication is not allowed during 1st trimester of pregnancy because possible effect of organ development. - Placenta appears 2nd month of pregnancy (8weeks) Fetal membrane The developing fetus will develop: 1. Chorionic – from chorion placenta arises (outer layer) 2. Amniotic – two structure arise from this are: bag of water/ amniotic sac that produces amniotic fluid and umbilical cord/ funic souffle (inner layer) - Funic souffle – souffle is the flow of the fetal blood. - Ingredients of placenta – decidua basalis and chorionic villi. - Human chorionic gonadotropin produces by chorionic villi. (Normal: 50k – 400k units) Amniotic fluid - Volume: 500-1200 ml; average is 1000 ml - Composition: 99% H2O, 1% solid particles; pH 7 – 7.25; solid particles: albumin, urea, uric acid, LECITHIN, SPHINGOMYELIN, bilirubin, vernix caseosa, is cheese like substance on the skin to lubricate the skin of the baby - Lecithin and sphingomyelin are very important because these are the precursors for the development of surfactant. (Surfactant lubricates alveoli for better lung expansion) - Bilirubin – the product of immature or destroyed RBC. If there will be blood incompatibility between the mother and the fetus more RBC of the baby will be destroyed kaya more bilurubin coming from the bile at kapag madami ito skin color of the baby will be yellow/ jaundice. - Purpose: • Ballottement/ movement • Protection to trauma/ injury • Protection from infection • Nourishment – fetus swallows amniotic fluid. • Serves as diagnostic specimen. (Amniocentesis – aspirations of amniotic fluid around 15-30 cc) • Thermoregulation - Specific test that will determine Fetal Lung Maturity is lecithin and sphingomyelin ratio • If LS ratio is 2:1 = there is fetal lung maturity. 2 lecithin in every 1 sphingomyelin then there is already fetal lung maturity. • Once the baby is delivered prematurely, since the LS ratio is at least normal, the baby will not have that much difficulty of breathing – respiratory distress. • 1:1 = the lungs are not yet matured. Once the baby is delivered the doctor will administer artificial surfactant. (ex. Survanta, aid lungs and alveoli to expand) - Nurses need to identify the color of the amniotic fluid once the bag of water ruptures when laboring - Normal Appearance: clear and colorless – straw colored • If green – fetal distress is non-breech either transverse or cephalic - Fetal distress – the baby difficulty of breathing inside the uterus of mother. - Baby breathing – is umbilical cord, this attached on the placenta and placenta attached on the uterus. - Placenta is the one giving the baby oxygen. - 3 parameters that we can check/ assess to determine fetal distress: a) Fetal heart rate – 120 -160 (early/initial responseof fetal distress: fetal tachycardia and late sign of fetal distress: bradycardia) b) Color of amniotic fluid (meconium – first stool/stain, kaya naging green yung amniotic fluid. Urine is common but defacte inside the uterus no) c) Fetal movement – you have to count the kick (Normal kick count: 1hour – 10 ave; min 5; max: 15; if more than 15 hyperactive fetus; if less than 5 hypoactive fetus; earliest sign in terms of fetal movement is hyperactive; late sign is hypoactive) - In breech presentation presenting part in the birth canal is the buttocks, it is expected to go down first and goes out the birth canal. As the baby goes out the birth canal the baby can compress the anal sphincter and the birth canal pressure the anal sphincter. As uterus is contracting baby is pushed downward. Therefore anus sphincter is pressed against narrowed canal that increase pressure in the anal sphincter so it relaxes and it opens and this will go out from the anus: ↓ - Meconium and will stain the amniotic fluid. It is not a sign of fetal distress because the baby is in breech. The baby defecates because of the pressure. Does not guarantee absence of fetal distress like if the baby had uteroplacental insufficiency - Breech presentation: If upon IE, there is meconium staining, YOU CANNOT ASSESS FETAL
NCMA217 LEC: WEEK 4 – FETAL DEVELOPMENT & MILESTONES (SIR VASQUEZ & MAM JHAL) J.A.K.E 2 of 6 DISTRESS BY CHECKING OR COUNTING THE AMNIOTIC FLUID because meconium staining is expected in breech but you are going to ASSESS the FHT, fetal movement, fetal kicks should be counted for 1hr. - In cephalic presentation the head is the presenting part in the birth canal so there is no reason to open the anal sphincter EXCEPT there is uteroplacental insufficiency – means if the placenta is not giving this baby good amount of oxygen. Had low oxygen supply so the anal sphincter relaxes. The lungs begin to expand so the baby starts trying inhaling through the mouth but it’s still located inside the uterus. Baby can inhale the amniotic fluid with meconium – this is more dangerous. It can reach the lungs that can lead airway of obstruction, fetal distress and to aspiration pneumonia and that could be possible cause of death. • If golden/yellowish – hemolytic disease; Rh or ABO incompatible - If the blood of the baby and mother is not compatible, the blood of mother will destroy the fetal RBC, they release bilirubin. • If gray – infection - STD Ex. Trichomonas vaginalis Umbilical cord - Function: transport oxygen and nutrients to fetus, unoxygenated blood, and water to placenta. - Waste products metabolism - The mother will be the one discard. - Blood vessels: 2 arteries and 1 vein - When you clamp and cut the cord, you will find 3 blood vessels. (AVA). Deoxygenated blood is flowing in umbilical arteries; oxygenated blood is umbilical vein. - If upon clamping and cutting the cord, you only found 2 blood vessels – means the missing one is one artery. Meaning: the baby has one renal artery because the baby has only one kidney. Notify the pedia immediately. - Length: 50-55 cm - If the length of the umbilical cord is less than 50 cm, the baby goes down the birth canal, the baby is pulling the placenta. That can lead to abruptio placenta – sudden separation of placenta from the uterus. - If the length of the umbilical cord is more than 55 cm, that can lead to cord coil or prolapse of the cord. - The cord is the inserted at the back. - Insertion: center of the placenta • Velamentous insertion – membrane • Battledore insertion – edge of placenta - Abnormalities: 1) Knots – may lead to perinatal loss, high in twins - Because of knotting, there is constant lack of oxygen supply and low nourishment supply. - SGA – yung head maliit pati ung brain maliit, so that can affect cognitive function. 2) Cord coil – nuchal cord, single or double, clamp + cut - Can also lead to abruption placenta - Once the baby is out, palpate the neck, check the umbilical cord if there is umbilical cord coiling around the neck, try to pull, loose – single; tight – double. - If there is double, clamp and cut the cord. 3) Tension of the cord – decreased Wharton’s jelly; stillbirth. - Wharton’s Jelly → it between the 3 blood vessels, there is gelatinous substance that cushions umbilical cord. If the amount of Wharton’s jelly is decreased the three-blood vessel are easily compressed. Placenta - From chorionic villi and decidua basalis - Weight = 500 gms at term; has 15 to 29 cotyledons - The cotyledons are being check after delivery of the placenta. - Produces: estrogen, progesterone, HPL and HCG - 2 sides: • Maternal – (dark and redish) this is abnormal – some of the lobes and cotyledons are detached and remains inside the uterus after delivery. The uterus cannot contract, cannot remain firm. Therefore, woman starts to bleed. • Fetal – (Shiny and grayish) - 2 Types of placental separation: • Schultz– placenta separate from center to periphery. Fetal side will be seen first. This is normal placental delivery. • Duncan – placenta separate from periphery to center. Placenta turns inside out. Maternal side is seen first. This is abnormal because some cotyledons detach and remains in the uterus and uterus cannot contract and not firm. MILESTONES OF FETAL DEVELOPMENT - Ovulation age – life of fetus from ovulation → Fertilization - Gestational age (AOG) – Length of pregnancy (1st day of LMP until birth) - Both ovulation age and gestational age are reported in lunar months (4 weeks) or measured by trimesters, we have 3 mos. in a trimester - Fetus grows in uterus in 9 1⁄2 lunar months or 3 full trimesters 38 weeks/ 266 days - Lunar months – consist of 4 weeks - 10 months of pregnancy = total of 40 weeks, 280 days - Intrauterine life – in uterus 1st trimester - The period of organogenesis. - Most critical period for fetal groth and development (kasi ito ung time na nag mamature, nag gogrow, nag dedevelop ang organs, pag nagkaproblema sa time na to, the baby will have congenital deformities) - Organogenesis – formation of organ begins 1st 2 months of pregnancy. Self-medication is not allowed during 1st trimester of pregnancy because possible effect of organ development. 1st month (1-4 weeks) - Heart functions as early as 16th day - Development – nervous system; maternal hypoglycemia - First sign in the development of NS is hypoglycemia because glucose is essential to the development of nervous system.
NCMA217 LEC: WEEK 4 – FETAL DEVELOPMENT & MILESTONES (SIR VASQUEZ & MAM JHAL) J.A.K.E 3 of 6 - Rudimentary heart appears as a prominent bulge on the anterior surface that is towards end of 1st month (1-4 weeks) - Arms and legs are buds like structure - Spinal cord, nafoform na at fused in the midline - Rudimentary eyes, nose, ears are already discernible 2nd month (5-8 weeks) - Sex differentiation starts - if the sex differentiation starts in 2 months of pregnancy, sex diff. completed in 4th month of pregnancy. - But the 4th month is not the best time that the woman will undergo ultrasound to be able to identify the gender of the baby, kase ang genetalia are still small. So, pwede sya ma pagkalaman na yung scrotum can be the labia then vice versa. - The fetus assumes human form - Presence of amniotic fluid - FHR determination by Doppler. - Vital organs are formed and developing. - By the end of month, almost complete organogenesis. - The heart is now with septum and valves. Starting to beat rhythmically. - Genitals – already forming but it cannot distinguish the gender yet. - Abdomen – starting to bulge. Medyo lumalaki na sya kasi nag gogrow na ung intestine sa loob. - Ultrasound – presence of gestational sac. Considered as diagnostic of pregnancy. (Positive sign of pregnancy) 3rd month (9-12 weeks) - Renal system is functional - Sucking reflex is present. (which is tamang tama dahil the fetus swallows the amniotic fluid, therefore kapag nilunok nya yung amniotic fluid the fluid will go to the gastrointestinal system. And thru absorption some of the fluid will be absorb could mix with the blood and go to the kidney) - Placenta is fully developed and functional - Sex is distinguishable - By the end of month, the fetal heart tone is already audible, by doppler - 9-12 weeks na ang baby so may buds na siya for milk teeth, teeth starts to form, nail beds also forms - Spontaneous movement ang galaw ni baby pero faint - Important to remember: • Heart functions as early in 16th day • Nervous development which is manifested by hypoglycemia in the part of the mother because glucose is unnecessary ingredient for the development of the nervous system • Sex differentiation starts in 2nd month of pregnancy • Fetal heart rate determination in second month • 3rd month renal system is functional 2nd trimester - Focuses on the length of the fetus 4th month (13-16 weeks) - FHT by fetoscope - Sex differentiation is complete (pwede na makita ung gender) - Quickening for multipara (quickening – fetal movement felt by the mother 16th weeks – multi gravid mother; 5th month of pregnancy for primigravida) - IgG transport from mother to fetus - Lanugo is well formed. (Lanugo start to disappear in 8th month) - The liver and pancreas are functioning. - Fetus actively swallows amniotic fluid. - Urine is also present in amniotic fluid. - Appearance of the buds for the permanent teeth in the gums. - Weight: 55- 120 gms 5th month (17-20 weeks) - Age of viability: 20th week (Range: 20-24 weeks) - Weight: 500-600 gms - Survival depends on the maturity of fetal nervous system. Maturity of lungs/ presence of lungs surfactant. - Vernix appears (disappear in 9 months) - FHT by stethoscope - Lanugo covers the body - Swallow amniotic - Spontaneous fetal movement (mafifeel na rin kahit first time pregnant) - Fetal stool, already present in upper intestine 6th month (21-24 weeks) - Surfactant production begins (Hearing can be demonstrated by the fetus as he/she response to sudden sound.) - Hears external sound – good time to talk and play to the baby - Vernix caseosa - Eyelids start to open - Skin is red and wrinkled - Focus on continues growth and development of fetus. - Pwede ng mapanganak, preterm, high risk. - Lungs surfactant – used to sweating agents to prevent alveolar walls from sticking and allowing the lungs to expand during extrauterine life. - Fetal stool, already in rectum. Kaya kapag fetal distress sya, pwede na magkaroon ng meconium staining. 3rd trimester - Period of rapid growth and development. Focus of growth is weight gain and adipose tissues. (kailangan ng adipose tissue para maging cute sya HAHAHA JOKE, to regulate body temperature once he is born) 7th month (25-28 weeks) - Continued growth and development - Bone ossification - Surfactant develops - Male testes start to descend in the scrotal sac, (dapat naka suspend sa scrotum ang testis) - Female clitoris is prominent. (mas pansin na) - Blood vessels and retina of the eyes are formed but extremely thin. If retina of the eyes is extremely thin, the fetus also extremely susceptible to damage kapag nag administer ng high oxygen concentration. - This is the good time for 3D ultrasound to determine the gender of the fetus. 8th month (29- 32 weeks) - Subcutaneous fat is present - Iron transfer from mother to fetus (going to provide iron in immediate extrauterine life) - Lanugo starts to disappear – fine downy hairs. Full term: no lanugo
NCMA217 LEC: WEEK 4 – FETAL DEVELOPMENT & MILESTONES (SIR VASQUEZ & MAM JHAL) J.A.K.E 4 of 6 - Nails extend to fingers. - Still considered as premature when delivered. - Response to movements by sounds inside the mothers body. - Moro reflex/ startle reflex is present - Weight: 1600 gms 9th month (33- 36 weeks) - Testes descends in scrotum - Lanugo and vernix caseosa disappear (vernix caseosa – cheese like substance, nakabalot sa buong katawan, cold protection) - Amniotic fluid somewhat decreases - Body stores of glycogen, sugar, iron, carbohydrate, and calcium are already deposited in the body. - Additional subcutaneous fats are also deposited. - Most fetus starts to position in cephalic. (pumupwesto na siya) - Weight: 2700 gms - Still considered as preterm when it delivered. 10th month (37-40 weeks) - Bone ossification of fetal skull begins - Full term; ready to be born - Fetus kicks actively which causes discomfort of the mother. - Creases on feet is on 2/3rd - Weight: 3000 gms, 7-7.5 pounds Fetal circulation - The heart is the first system that is functional as early as the 4th week of AOG. - Normal at birth: 120-160 per minute, By a Doppler: 10-12 weeks; using fethoscope/stethoscope by: 18-20 weeks. - May difference sa heart ng baby at adult kasi may temporary structures ang baby, at a certain time mag ko-closed or mawawala yan. Temporary structures • Placenta – source of nutrients and gas exchange. Connected to the mother. • Foramen ovale – opening between the right atrium and left atrium. In adult circulation there is no opening between the two chambers • Ductus Venosus – connection between the umbilical veins and inferior vena cava to bypass the immature fetal liver. (temporary bypass; vein to vein connection) • Ductus arteriosus – connection between the pulmonary artery and aorta in order the blood to bypass the lungs. (artery to artery) So that the majority of the blood won’t go to the lungs because the fetal lungs are still immature. Some of the blood will still go to the liver and to the lungs in order to provide nourishment. But the majority of the blood will bypass them because those structures are still immature. • Umbilical cord – AVA (in fetus, 2 arteries – carries deoxygenated blood and 1 vein – carries oxygenated blood) by this the baby will breath. - Fetal circulation differs from uterine circulation because fetus derives oxygen and excretes carbon dioxide, not from gas exchange, but from the exchange in the placenta. - Fetal circulation differs from extra uterine circulation because the fetus derives oxygen and excretes carbon dioxide not from gas exchange in the lungs but from the exchange in the placenta. - Fetal circulation in the utero depends on the use of shunts to pull blood away from the lungs. While laboring the fetus expel the fluids in its body as well as fluids in the lungs. That’s why we use surfactants - Before birth: coming from the mother → uterus → placenta - Blood arriving at the fetus from the placenta is highly oxygenated. - The blood enters to fetus through the umbilical vein. Hanggang maabot sa immuture liver ni baby. We have specialize structures that are present in the fetus in order to shunt blood flow to first supply the important organs like heart, kidney, and brain. Blood flow from the umbilical vein to ductus venosus which is an accessory vessel that discharges oxygenated blood into the immature fetal liver for its development. - Pagdaan ni oxygenated blood sa liver, mag iiwan sya ng konting oxygenated blood pero majority of the blood will bypass that area to ductus venosus. (Which is considered to be accessory vessel that discharges oxygenated blood into the immature liver for development) - This ductus venosus is connected to the fetal inferior vena cava. So that the oxygenated blood is directed to right atrium of the heart hindi nya kailangan ng blood supply papunta sa lungs, sa adult circulation – the blood coming from the right atrium bababa sa right ventricle papunta sa lungs pero dahil oxygenated na yung blood, hindi na kailangan ng ganon. The Bulk of the blood is being diverted thru an opening in atrial septum called the foramen ovale. Instead na ang blood ay bababa from RA to LA hindi na ito matutuloy, isha-shunt na lang siya patawid. In adult circulation, instead from the RA bababa sa RV hindi na ito mangyayari tatawid na lang siya sa foramen ovale from RA to LA - Pag dating sa LA it will follow adult circulation. From LA bababa ang blood passing through the tricuspid valve towards the LV. From LV it will be thrown out through the aorta to oxygenate the various organs of the body that includes upper portion like brain. - Small amount of blood that returns to heart using vena cava hindi na makakalabas ng RA. It will follow adult course at bababa through tricuspid valve into the RV and into the pulmonary artery to the lungs to help the lungs development and maturity. - Ductus arteriosus – from the heart, papunta naman sya sa descending aorta. It will oxygenate the lower part of the body. As the majority of the blood cells of aorta become deoxygenated, the blood is being transported from the descending aorta thru the 2 umbilical arteries that carries unoxygenated blood away from the heart pabalik kay mommy for oxygen exchange. - At birth infants saturation is: 95-100%; Pulse rate: 180 bpm - Because of great deal of mixing blood in the fetus yung oxygen level niya minsa ay hanggang 80% lng at ok lang yun. Heart rate: 110/160 din minsan. - Temporary structures will be closed if baby is delivered but if not babay will have heart defects. Like patent ductus venosus, ductus arteriosus and foramen ovale.