Ch 9-12 Lecture Flashcards
chorionic villi sampling
Small sample of chorionic villi taken from developing placenta (the villi arise from the trophoblast cells, their chromosome structure is the same as the fetus)
Done Vaginally, with abdominal ultrasound
early in pregnancy 10-12 weeks
Performed in some medical centers for first-trimester diagnosis of genetic and deoxyribonucleic acid (DNA) studies
-Used for genetic testing
amniocentesis
A small amount of amniotic fluid is removed by a needle aspiration
Early detection can evaluate for Chromosome Analysis-Genetic Disease (Trisomy 21) 15-18 weeks
- Down’s Syndrome
- Smaller trisomy #’s (16, 18) not compatible with life
L/S ratio Can determine lung maturity-Later in pregnancy
-Lecithin and sphingomyelin are the components of the lung enzyme surfactant
alpha fetal protein
a non-specific test taken at around 15-20 weeks that can detect spinal or abdominal wall defects and genetic disorders
Not a definitive test, will need another test to confirm
ultrasound
transabdominal and transvaginal (probe into vagina)
Used to:
i. Identifying pregnancy and determining gestational age as early as 5 or 6 weeks
ii. Identifying fetal heart rate and fetal breathing movements
iii. Detect fetal death – via absent FHR
iv. Estimating size of the fetus: Measure biparietal diameter of head, femur length, estimate weight
v. Screen for fetal anomalies such as facial, anencephaly, hydrocephalus
vi. Identify placental location and grading
vii. Detect fetal position and presentation
viii. Assist with accompanying procedures (Amniocentesis)
maternal assessment of fetal activity
Count fetal movements at the same time each day/Kick counts
Begins at approximately 28 gestational weeks
Reduction in movement may indicate fetal hypoxia, growth restriction, or fetal death
McDonald’s Rule
a measurement of fundal height
Measurement is from the notch of the symphysis pubis to over the top of the uterine fundus. Usually done in cm which correlates to weeks pregnant.
Example 34 weeks = tape measure should be 34 cm
Non-Stress Test (NST)
Widely used method of evaluating fetal status (alone or as part of biophysical profile [BPP)
Requires electronic monitor to observe and record fetal heart rate accelerations
Adequately oxygenated fetus with intact fetal central nervous system should demonstrate accelerated fetal heart rate (FHR) in response to fetal movement
Reactive results of non-stress test
Desired result
Shows at least two accelerations of FHR with fetal movements of 15 beats/min, lasting 15 seconds or more, over 20 minutes
In preterm fetuses, rate is 10 beats above baseline for 10 seconds in a 20-minute window
Fetal Acoustic and Vibroacousting Simulation test (FAST and VST)
used in conjunction with NST
Handheld, battery-operated device applied to woman’s abdomen over fetal head. Device generates low-frequency vibration and buzzing sound.
Stimulation induces movement and accelerations of fetal heart rate (FHR) in fetuses with nonreactive NST
- Stimulus lasts for 2‒5 seconds;
- if no accelerations, then repeated at 1-minute intervals up to 3 times
Biophysical Profile (BPP)
an ultrasound that uses 5 variables to score a baby. It helps either to identify the compromised fetus or to confirm the healthy fetus and provides an assessment of placental functioning
Performed after 28 weeks
BPP is scored on 5 variables. They are:
- Fetal breathing movement
- Fetal movements of body or limbs
- Fetal tone (extremity extension and flexion)
- Fetal reactivity (Reactive fetal heart rate (FHR) with activity (reactive non-stress test [NST])
- Amniotic fluid volume (pockets of fluid around the fetus)
BPP Scoring Criteria
(Score of 2 assigned to each of the 5 areas):
1. A Score of 8-10 is a normal finding
2. A score of 6 is suspicious
3. A score of 4 denotes a fetus potentially in jeopardy
4. Maximum score of 10
Contraction Stress Test (CST)
test done during contractions that a. evaluates placental respiratory function (oxygen and carbon dioxide exchange).
A positive test shows late decels with each contraction. NOT A DESIRED RESULT.
A negative CST implies normal placental function, adequate fetal oxygenation, and that the fetus will likely withstand the stress of labor.
In many settings, CST has been replaced by biophysical profile (BPP)
Before pregnancy the uterus is small, solid, weighs about 60grams and can hold about 10 ml. During pregnancy it increases in size, and at the end of pregnancy it weighs about __.
1100 grams and can hold 5000ml
Hegar’s sign
Cervix (normally stiff) becomes loose and pliable
Goodell Sign
softening of the cervix
chadwick’s sign
bluish discoloration of the cervix
___ progressively increases beginning in the first trimester, increases rapidly until about 30-34 weeks.
Blood volume
Cardiac output and blood volume increases with an increased workload-pulse may increase 10-15 beats per minute.
Increased CO and blood volume is the reason they advise some women with complex heart issues NOT to get pregnant.
Supine hypotensive syndrome
Pregnant women lies supine, the uterus presses on the vena cava.
This may reduce blood flow to the right atrium, lowering blood pressure and causing dizziness, pallor and diaphoresis.
This can be corrected by lying on her left side or placing a pillow under the right hip .
facial chloasma
also known as the “mask of pregnancy” a darkening of the skin over the forehead and around the eyes.
linea nigra
line in the middle of the abdomen which usually extends from the pubic area to the umbilicus or higher
recommended weight gain during pregnancy
25 to 35 lb
Overweight: Recommended gain is 15 lb
Underweight: May gain up to 40 lb
subjective or presumptive changes indicating pregnancy that a woman experiences. These could be caused by other conditions and are NOT PROOF OF PREGNANCY.
a. Amenorrhea
b. Nausea and vomiting
c. Fatigue
d. Urinary frequency
e. Breast changes
f. Quickening (felt fetal movement)
objective or probably changes indicating pregnancy that an examiner can perceive. These could be caused by other conditions and are NOT PROOF OF PREGNANCY.
a. Goodell and Chadwick signs
b. Hegar and McDonald signs
c. Enlargement of the abdomen
d. Braxton Hicks contractions
e. Uterine soufflé
f. Skin pigmentation changes
g. Pregnancy tests:
Serum (blood) tests- (detect hCG)
Urine tests
NOTE: Hydatidiform mole has positive pregnancy test, but is not a real pregnancy
Therefore a pregnancy test is not a definitive proof of pregnancy.
Definitive proof of pregnancy. These three things offer conclusive proof of pregnancy:
Fetal heartbeat
Fetal movement (visualized)
Visualization of the fetus
TPAL
(1) T - Number of term infants born (completion of at least 37 weeks’ gestation)
(2) P - Number of preterm infants born (after 20 weeks’ but before 37 weeks’ gestation)
(3) A - Number of pregnancies ending in spontaneous or therapeutic abortion
(4) L - Number of currently living children
Nägele’s rule
used to determine due date
First days of LMP, subtract 3 months, add 7 days
quickening
fetal movement, usually felt around 20 weeks
fetal heart rate
usually found about 12 weeks by doppler
teratogens
Maternal infections that affect fetus: Malaria, Rubella (German measles), Toxoplasmosis, Herpes simplex virus (HSV), Cytomegalovirus – found in cat litter, Syphilis
Infections that cause illness at birth: Gonorrhea, Candidiasis, Chlamydia, Streptococcus B, Hepatitis B,
also: Live virus vaccines Herbs Alcohol Tobacco Environmental: Metal and chemical hazards, Radiation, Hyperthermia and hypothermia Maternal stress Medications
