Fetal Development Stages PDF

MATERNAL BABY **Terms used to Denote Fetal Growth** **Ovum**- From ovulation to fertilization **Zygote**- From fertilization to implantation **Embryo**- From implantation to 5-8 weeks **Fetus**- From 5-8 weeks until term **Conceptus**- Developing embryo or fetus and placental structures throug...

MATERNAL BABY **Terms used to Denote Fetal Growth** **Ovum**- From ovulation to fertilization **Zygote**- From fertilization to implantation **Embryo**- From implantation to 5-8 weeks **Fetus**- From 5-8 weeks until term **Conceptus**- Developing embryo or fetus and placental structures throughout pregnancy **Age of viability**- The earliest age at which fetuses could survive if they were born at that time, generally accepted as 24 weeks, or fetuses weighing more than 400 g  **Fetal Growth and Development** End of Fourth Gestational Week - The length of the embryo is about 0.75 cm, weight is about 400 mg - The spinal cord is formed and fused at the midpoint. - The head is large in proportion and represents about one third of the entire structure. - The rudimentary heart appears as a prominent bulge on the anterior surface. - Arms and legs are bud-like structures; rudimentary eyes, ears, and nose are discernible. End of Eighth Gestational Week - The length of the fetus is about 2.5 cm (1 in.); weight is about 20 g - Organogenesis is complete. - The heart, with a septun and valves, beats thythmically: - Facial features are definitely discernible, arms and legs have developed. - External genitalia are forming, but sex is not yet distinguishable by sunple observation. - The abdomen bulges forward because the fetal intestine is growing so rapidly End of 12th Gestational Week (First Trimester) - The length of the fetus is 7 to 8 cm; weight is about 45 g. - 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 begin to form. - Tooth buds are present. - Sex is distinguishable on outward appearance - Urine secretion begins but may not yet be evident in amniotic fluid. - The heartbeat is audible through Doppler technology. End of 16th Gestational Week - The length of the fetus is 10 to 17 cm; weight is 55 to 120 g. - Fetal heart sounds are audible by an ordinary stethoscope. - Lanugo is well formed. - Both the liver and pancreas are functioning - The fetus actively swallows amniotic fluid, demonstrating an intact but uncoordinated swallowing reflex, urine is present in amniotic fhuid - Sex can be determined by ultrasonography. End of 20th Gestational Week - The length of the fetus is 25 cm, weight is 223 g. - Spontaneous fetal movements can be sensed by the mother. - Antibody production is possible. - Hair, including eyebrows, forms on the head; vernix caseosa begins to cover the skin. - Meconium is present in the upper intestine. - Brown fat, a special fat that aids in temperature regulation, begins to form behind the kidneys, sternum, and posterior neck. - Passive antibody transfer from mother to fetus begins. - Definite sleeping and activity patterns are distinguishable as the fetus develops End of 24th Gestational Week (Second Trimester) - The length of the fetus is 28 to 36 cm; weight is 550 g. - Meconium is present as far as the rectum. - Active production of lung surfactant begins. - Eyelids, previously fused since the 12th week, now open; pupils react to light. - Hearing can be demonstrated by response to sudden sound. - When fetuses reach 24 weeks, or 500 to 600 g, they have achieved a practical low-end age of viability if they are cared for after birth in a modem intensive.com nursery. End of 28th Gestational Week - The length of the fetus is 35 to 38 cm; weight is 1,200 g. - Lung alveoli are almost mature; surfactant 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 formed but thin and extremely susceptible to damage from high oxygen concentrations (an important consideration when caring for preterm infants who need oxygen). End of 32nd Gestational Week - The length of the fetus is 38 to 43 cm, weight is 1,600 g. - Subcutaneous fat begins to be deposited (the former stringy, \"little old man\" appearance is lost). - Fetus responds by movement to sounds outside the mother\'s body. - An active Moro reflex is present. - Iron stores, which provide iron for the time during which the neonate will ingest only breast milk after birth, are beginning to be built. - Fingemails reach the and of fingertips End of 36th Gestational Week - The length of the fetus is 42 to 48 cm, weight is 1.500 to 2,700 g (5 to 6 lb). - Body stores of glycogen, iron, carbohydrate, and calciomu are deposited - Additional amounts of subcutaneous fat are deposited - Sole of the foot has only one or two crisscross creases compared with a full crisscross pattern evident at term. - Amount of lanugo begins to diminish. - Most fetuses turn into a vertex (head down) presentation during this mouth End of 40th Gestational Week (Third Trimester) - The length of the fetus is 48 to 52 cm (crown to rump, 35 to 37 cm), weight is - 3,000 g (7 to 7.5 lb). - Fetus kicks actively, sometimes hard enough to cause the mother considerable discomfort. - Fetal hemoglobin begins its conversion to adult hemoglobin/ Vernix caseosa starts to decrease after the infant reaches 37 weeks gestation and may be more apparent in the creases than the covering of the body as the infant approaches 40 weeks or more gestational age. - Fingernails extend over the fingertips. - Creases on the soles of the feet cover at least two thirds of the surface - In primiparas (ie, women having their first baby), the fetus often sinks into the birth canal during the last 2 weeks of pregnancy, giving the mother a feeling the load **McDonald\'s rule** (symphysis-fundal height measurement) - Fundal height is measured in centimeters from the pubic symphysis to the top most portion of the uterus Measuring fetal heart rate with a Doppler transducer, which detects and broadcasts the fetal heart rate to the parent-to-be as well as to the nurse. Rhythm strip and nonstress testing of fetus heart - The woman sits in a comfortable chair to avoid supine hypotension. Both a uterine contraction monitor and fetal heart rate monitor are in place on her abdomen **Signs of pregnancy** - Presumptive signs - least indicative, could easily indicate other conditions - Probable signs - objective so can be documented by an examiner. - Positive signs - Demonstration of a fetal heart separate from the mother\'s - Fetal movements felt by an examiner - Visualization of the fetus by ultrasound    **Estimates of EDC** Maternity L&D DUE DATE FORMULA Naegel\'s Rule - When the LMP falls between April-Dec - LMP Date - Subtract 3 months Add 7 Days then Add 1 Year - When the LMP falls between Jan - Mar - LMP Date- Add 7 Days then add 9 months **Date of Quickening (Q)** Primigravida: - Date of Q + 4 months +20 days - Ex..Q-April 5, 2020= August 25, 2020 Multigravida: - Date of Q + 5 months + 4 days - Ex..June 20, 2020-Nov. 24, 2020 **To estimate AOG** - Mc Donalds Rule (Fundic Height) - Formula: Ht in cm x 2/7= duration in months - Formula: Ht. in cm x 8/7=duration in weeks - Bartholomew\'s Rule of four - Level of xiphoid process= 9 months - Level of umbilicus= 5 months - Level of symphysis pubis= 1 month **Estimated Fetal Weight** - Rump to crown length in utero in cm - CRL in uterus in cm x 100 = weight in gm  **Terms Related to Pregnancy Status** Para - Number of pregnancies that have reached viability, regardless of whether the infants were born alive Gravida - Woman who is or has been pregnant Primigravida - Woman who is pregnant for the first time Primipara - Woman who has given birth to one child past age of viability Multigravida - Woman who has been pregnant previously Multipara - Woman who has carried two or more pregnancies to viability Nulligravida - Woman who has never been and is not currently pregnant Example - A woman who has had two previous pregnancies, has given birth to two term children, and is again pregnant is gravida 3, para 2. - A woman who has had two miscarriages at 12 weeks (under the age of viability) and is again pregnant is a gravida 3, para 0. **Classifying pregnancy status(GTPAL or GTPALM)** - T: (Term)Number of full-term infants born (infants born at 37 weeks or after) - P: (Preterm) Number of preterm infants born (infants born before 37 weeks) - A: (Abortion) Number of spontaneous miscarriages or therapeutic abortions - L: Number of living children - M: Multiple pregnancies