Prenatal Diagnosis and Care Flashcards
First trimester
1st 14 weeks GA
Gestational Age
age in days or weeks from the last menstrual period
Second trimester
14-28 weeks GA
Third trimester
28 weeks until delivery
Previable
infant delivered before 24 weeks
Preterm
24-37 weeks
Term
37-42 weeks
Post term
past 42 weeks
What happens to moms cardiovascular system when pregnant
- CO increases by 30 to 50%
- stroke volume increases 10 to 15%
- pulse increases 15 to 20 bpm
- systolic ejection murmur and S3 gallop common
What happens to a pregnant womans blood pressure
- peripheral vascular resistance falls
- fall in BP in 2nd trimester, returns to normal in 3rd
What parts of the respiratory system remain unchanged during pregnancy
- respiratory rate
- vital capacity
- inspiratory reserve volume
What parts of the respiratory system change during pregnancy
Decreased: functional residual capacity, expiatory reserve volume, residual volume, total lung capacity
Increased: inspiratory capacity, tidal volume
Normal ABG from a pregnant lady
pH: 7.44, pCO2=30, bicarb=20-25, pO2>=100
What happens to the renal system during pregnancy
- increase kidney size and weight
- ureteral dilation
- bladder becomes intra abdominal organ
- GFR increases 50%
- creatinine clearence increases 150 to 200 cc/min
- BUN and SCr decrease by 25%
- increase in renin and angiotensin
- increased glucose excretion
What happens to the hematologic system during pregnancy
- plasma volume increases by 50%
- RBC volume increases by about 30%
- WBC count increases
- platelets decrease
- increased levels of fibrogen, factor Vii-X
- placenta produces plasminogen activator inhibitor
What happens to the GI system during pregnancy
- decreased motility
- reduced gastric acid secretion
TVUS shows gestational sac as early as ___ wks or Hcg of ___. Fetal HR as early as ___ or Hcg of ___.
gestational sac: 5wks or Hcg of 1,500-2,000
FHR: 6 wks or Hcg of 5,000-6,000
Chadwick’s sign
bluish discoloration of vagina and cervix
Hegar’s sign
softening of uterine consistency and ability to palpated or compress the connection between the cervix and the fundus
Goodell’s sign
softening and cyanosis of cervix at or after 4 weeks
Ladin’s sign
softening of the uterus after 6 weeks
Signs of pregnancy
- breast swelling and tenderness
- linea nigra
- telangiectasias
- palmar erythema
What is Nagele’s rule
calculate EDC by subtracting 3 months from the LMP and adding 7 days
First trimester labs
- CBC
- blood type and screen
- RPR/VDRL
- rubella antibody screen
- hep B surface antigen
- VZV titer
- STD cultures
- PPD
- pap smear
- urine
When do you check CBC in pregnancy
initial labs and 28 weeks
When should you consider thalaseemia in pregnancy
if MCV low
Normal CBC findings with pregnancy
- slightly elevated WBC
- dilutional anemia
- thrombocytopenia
What do you do if pt is Rh negative
Rhogam at 28 weeks or anytime she has vaginal or uterine bleeding
What do you do if Rh antibodies are found
consult perinatologist: Rh antibodies cause fetal red blood cells to be destroyed causing hemolytic anemia
What do you do if gonorrhea and chlamydia is positive
treat pt and partner, promote abstinence during treatment and test again 4 weeks after treatment
If RPR/VDRL is reactive what do you do next
Fluorescent treponemal antibodi absorption- check presence of antibody to bacteria that causes syphilis
What do you do if pt is non immune to rubella
administer vaccine post partum
HBsAb shows what
recovery and immunity
HBeAg shows what
acute infection
What is acute hep B infection diagnosed by
IgM HbcAb
What is chronic hep B infection diagnosed with
IgG HBcAb
Advanced maternal age
women over he age of 35
What should be offered to pregnant women of advanced maternal age
- maternal serum screening
- genetic counseling with possible diagnostic tests
Elevated MSAFP during the second trimester tells you
increased risk of NT defects
Decreased MSAFP in second trimesters tells you
aneuploidies including down syndrome
What is a quad screen
test done during the second trimester
includes MSAFP, HCG, estriol, inhibin-A
When is a quad screen done
between 15-18 weeks
When can you not do a quad screen
multiple gestations
What do you do if quad screen is positive
- refer for genetic counseling
- high resolution US
- +/- amniocentesis
What does cffDNA test for
fetal trisomies- 21,18,13
When should cffDNA be done
- maternal age over 35
- FUS findings indicating an increased risk of aneuploidy
- hx of prior pregnancy w/ trisomy
- postive rest result for aneuploidy
- parental balanced robertsonian translocation with increased risk of fetal trisomy 13 or 21
When should ultrasounds be done during pregnancy
- at minitial visit to measure CRL if uncertain LMP
- first trimester bleeding
- anatomy survey between 18 and 20 weeks
- any time fundal height is >3cm discrepant from GA
- confirm presentation at or after 37 weeks
When is amniocentesis done? Why?
done between 15-20 weeks to obtain fetal karyotype
What are the complications of an amniocentesis
- transient vaginal spotting
- amniotic fluid leakage
- preterm labor
- chorioamnionitis
- rarely needle injury to fetus
When is chorionic villus sampling done? Why?
done between 10-13 weeks to obtain a fetal karyotypes
How is a CVS done
catheter placed into intrauterine cavity and small amount of chrorionic villi aspirated from placenta
Complications of CVS
- preterm labor
- PROM
- previable delivery
- fetal injury
Cordocentesis
percutaneous umbilical blood sampling
When is PUBS done
rarely done but may be useful to further evaluate chromosomal mosaicism discovered after CVS or amniocentesis
Diagnostic done during the third trimester
- CBC
- GLT
- RPR/VDRL
- CXR if PPD+
- group B strep culture
if high risk:
- repeat gonorrhea and chlamydia
- HSV screening
When is group B strep culture done
36 weeks, culture from lower vagina and anus (swab must go through sphincter)
What things are done at all routine prenatal visits
- BP
- weight
- urine (protein and glucose)
- fundal height, estimated fetal weight, fetal position)
- asculatation of fetal heart tones
When should a pregnant woman have routine prenatal visits
less than 28 weeks: every 4 weeks
28-36 weeks: every two weeks
> 36 weeks: every weeks
How much folic acid should a pregnant lady be having
800 mcg
What supplements should be avoided in pregnancy
excessive fat soluble vitamins (A,D,E,K)
Caffeine limit in pregnancy
500mg/day
How many calories hsould be consumed a day in pregnancy? Protein? Iron? Calcium?
increase 15% kcal/day (2200)
additional 10-30 g protein
30-60 mg iron
1200mg calcium
Average weight gain during pregnancy
25 to 35 pounds
Indication for fetal movement assessment
maternal perception of decreased or absent fetal movement
What does a fetal non stress test measure? What is normal? Abnormal?
-measurement of fetal heart rate with movement
normal=2 or more fetal heart rate accelerations within a 20 minute period
nonreactive=insufficient fetal heart rate accelerations over a 40 min period
What does a contraction stress test look for
the presence or absence of late fetal heart rate decelerations in response to uterine contractions
What are late decels
decels that reach their nadir after the peak of the contractions and usually persist beyond the end of the contraction
Variable decels= ???
cord compression
What are the components of a biophysical profile
- NST
- fetal breathing movements
- fetal movements
- fetal done
- AFI (amniotic fluid index)
Scoring of the biophysical profile
each component gets a 2 or 0
normal: 8 or 10
equivocal: 6
abnormal: 4 or less
What is the amniotic fluid index
summation of the largest cord-free vertical pockets in each of the 4 quadrants of an equally divided uterus
Oligohydramnios
no US measured pocket of fluid >2cm
OR
AFI of 5 cm or less
Polyhydramnios is an AFI of
typically greater than 24 cm
Polyhydramnios can cause what two things
PROM or malpresentation
Postpartum visits for vaginal delivery. Cesarean.
Vaginal: at 6 weeks
Cesarean: 2 and 6 weeks
When should you consider sooner post -partum followup appointments
if complications present (3rd or 4th degree tear, HTN)
