The rest of Maternal for MIDTERM Flashcards
From ovulation to fertilization
OVUM
From fertilization to implantation
ZYGOTE
From implantation to 5-8 weeks
EMBRYO
From 5-8 weeks until term
FETUS
Developing embryo or fetus and placental structures throughout pregnancy
CONCEPTUS
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
AGE OF VIABILITY
Liz Calhorn asks how much longer her doctor will refer to the baby inside her as an embryo. The conceptus is an embryo
a. Until the time of fertilization.
b. Until the placenta forms.
c. From implantation until 20 weeks.
d. From implantation until 5 to 8 weeks.
d. From implantation until 5 to 8 weeks.
● 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 Fourth 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 septum and valves, beats rhythmically.
● Facial features are definitely discernible; arms and legs have developed
● External genitalia are forming, but sex is not yet distinguishable by simple observation.
● The abdomen bulges forward because the fetal intestine is growing so rapidly
End of Eighth Gestational Week
● 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 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 12th Gestational Week (First Trimester)
● 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 fluid.
● Sex can be determined by ultrasonography.
End of 16th 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
● biorhythms that will guide sleep/wake
patterns throughout life.
End of 20th Gestational Week
● 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 modern intensive care nursery.
End of 24th Gestational Week (Second Trimester)
● 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 28th Gestational Week
● The length of the fetus is 38 to 43 cm: weight is 1.600 g.
● Subcutaneous fat begins to be deposited in the former stringy. “little old man” appearance is lost).
● Fetus responds by morement 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.
● Fingernails reach the end of fingertips.
End of 32nd Gestational Week
● The length of the fetus is 42 to 48 cm; weight is1,800to2,700g(5to61b).
● Body stores of glycogen, iron, carbohydrate, and calcium 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 month
End of 36th Gestational Week
● 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 16).
● 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 she is carrying is less. This event, termed lightening, is a fetal announcement that the fetus is in a ready position and birth is nearing.
End of 40th Gestational Week (Third Trimester)
symphysis-fundal height measurement
McDonald’s rule
least indicative, could easily indicate other
conditions
Presumptive signs
objective so it can be documented by an examiner
Probable signs
● Demonstration of a fetal heart separate from
the mother’s
● Fetal movements felt by an examiner
● Visualization of the fetus by ultrasound
Positive signs
an imaging test that uses sound waves to make pictures of organs, tissues, and other structures inside your body
Ultrasonography
list some examples of presumptive sign of pregnancy
-breast changes
-nausea, vomiting, amenorrhea
-frequent urination
-fatigue
-uterine enlargement
-quickening
list some examples of probable signs of pregnancy
-serum laboratory
-Chadwick’s sign
-Goodell’s sign
-Hegar’s sign
-evidence on ultrasound of gestational sac
-ballottement
