Antenatal fetal assessment and IUGR

Question 1

what are the goals of fetal surveillance

Answer 1

prevent fetal death

prevent neonatal morbidity

Question 2

what are some ways to assess fetal wellbeing in the office

Answer 2

s/sx of disorders of hx–> gestational HTN, general maternal health

fetal movement–at least 6 movements within 2 hours, starting after 26 weeks

BP

maternal weight gain

symphysis-fundal height (SFH)

fetal HR with doptone

Question 3

indications for antenatal fetal assessment/surveillance

Answer 3

pre-existing medical conditions–> pre-existing diabetes, hypertension, cardiac disease, lupus

pregnancy related–> multiple gestation, oligohydramnios, postdates, PPROM, 2nd/3rd trimester bleeding (?abruption or placenta previa)

previous fetal demise

Question 4

what does oligohydramnios make us worry about?

Answer 4

amniotic fluid is a measure of fetus fluid status–> i.e low amniotic fluid means baby urine output is down–> sign of poor placental perfusion

Question 5

define IUGR

Answer 5

estimated fetal weight is less than 10th percentile

abdominal circumference is less than 10th percentile

includes many normal fetuses–> 25-75% are constitutionally small

excludes fetuses that stopped growing

clinical definition postnatally is birth weight below the 10th percentile

Question 6

how does SGA differ from IUGR

Answer 6

IUGR is pathological, SGA can be normal and just happens to be small

Question 7

symmetrical IUGR definition

Answer 7

all measurements are small for GA

likely due to:
congenital infection 
chromosomal abnormality
congenital malformation
maternal drug ingestion
alcohol abuse 
genetic syndromes
constitutional

Question 8

asymmetrical IUGR

Answer 8

this is likely due to deficiency in nutrients

results in large head (because spares nutrients for brain) whereas rest of body is small

mostly a placental functioning issue

Question 9

why do we care about IUGR

Answer 9

second most common cause of perinatal mortality

fetal death increases x8 between the 10th and 3rd percentiles

fetal death is x20 when birth weight is less than 3rd percentile

30% of infants who die of SIDS were IUGR

more susceptible to asphyxia

higher rates of meconium aspiration

hypoglycemia due to decreased glycogen reserves

hypocalcemia–> second to hyperparathyroid

hypothermia

polycythemia–x3-4

hypercoagulability

hyperbilirubinemia–due to polycythemia

thrombocytopenia

Question 10

what usually causes variable decelerations

Answer 10

cord compressions–not too worrying

Question 11

what usually causes late decelerations

Answer 11

hypoxia–worry–consider making sure delivers quickyl

Question 12

what usually causes decelerations timed with contractions

Answer 12

head compression/vagal response from fetus–not too worrying

Question 13

how do you interpret a BPP score

Answer 13

any score 4 or less–> DELIVER BABY

Question 14

how much of the placenta has been affected (placental arteries obliterated) when you get reversed end-diastolic flow

Answer 14

70%

measuring end diastolic flow (biophysical profile–BPP) with doppler is the one test we have that actually can have an impact on fetal outcomes

Question 15

how often do you check fetal growth when monitoring for IUGR

Answer 15

every 2 weeks