fetal complications part I

Question 1

IUGR vs SGA

Answer 1

• IUGR = small b/c of pathology

- SGA = small, <10th percentile

Question 2

causes of symmetric vs asymmetric IUGR

Answer 2

• HC vs AC

symmetric

• early insults
• genetics, infections

asymmetric

• later insult
• placental insufficiency
• impair cell hypertrophy
• AC lags first (liver)

Question 3

most important RF for IUGR

Answer 3

hx of IUGR

Question 4

causes of IUGR

Answer 4

Fetal

• chromosomal/trisomy
• anomalies
• infection (rarer): CMV, rubella, toxo, HSV, varicella, syphilis (TORCH)

Placenta

• infarction
• previa
• circumvallate
• prolonged preg
• accreta
• twins: fall off at 28wks

Mom

• vascular: HTN disorder, DM
• maternal hypoxemia (cyanotic heart disease, obstructive lung)
• caloric restriction
• smoking
• alcohol, coumarin, hydantoin

Question 5

risks of IUGR

Answer 5

• asphyxia - diminished placental reserve
• cord compression from oligo
• hypoglycemia - less glycogen
• hypoparathyroidism -> hypocalcemia
• hyperP - tissue breakdown
• hypoNa - renal function
• polycythemia from hypoxia -> hyperbilirubinemia
• childhood metabolic syndrome?
• neurologic?

Question 6

diagnosing IUGR

Answer 6

• accurate dates - first trim US CRL
• HC, AC, BPD, FL on US
• HC/AC ratio - elevated in asymmetrical (is 1 at 32 wks)
• FL/AC if HC can’t be measured (>23.5 - elevated after 21 wks)
• fluid <2cm associated /w IUGR
• EFW (not that accurate)
• serial assessments helpful

FL/AC + fluid doesn’t rely on dates, use if inaccurate dating

Question 7

management of IUGR

Answer 7

deliver if:

• abnormal function
• no growth
• severe oligo

tx etiology

• stop smoking, EtOH, drugs
• tx HTN, asthma, IBD
• rest may me helpful
• adequate diet

US for congenital abnormalities:
- symmetric: follow /w cord sample, placental biopsy or amnio if desired to r/o lethal anomalies

monitor:

• US for growth every 2-3 wks
• NST 2x/ week
• BPP
• dopplers
• no consensus on how often

if unknown dates:
- growth rate below 5th percentile prob IUGR

Question 8

intrapartum management of IUGR

Answer 8

• cont FHR monitor
• scalp pH if needed
• consider C/S if deterioration antepartum and cervix is unfavorable (vs induction)

Question 9

causes of congentical anomalies

Answer 9

chromosomal
genetic
drugs/chemicals
infection
radiation
unknown - most

Question 10

screening/RF for congenital anomaly

Answer 10

• AMA (aneuploidy)
• Ethicities: Jews, Frnch Can, Cajun (tay sachs), CF (whites), Asian, African (alpha thal), Mediterranian, SEA (beta thal), sickle cell (african)
• prev hx
• parental carrier of balanced rearragnement
• multiple losses
• consanguinity

Current preg with:

• US abnormality
• abnormal serum marker
• exposure to teratogen

Question 11

counselling process

Answer 11

• questionnaire
• 3 gen pedigree
• non directive
• after birth of abnormal neonate, wait 6 wks for definitive counselling

Question 12

polyhydramnios definition + causes

Answer 12

• AFI >25cm or max vertical pocket >8cm
• anencephaly
• absent stomach
• esophag or duodenal atresia
• tracheo esoph fistula
• neuromusc disese
• maternal DM (milder)

Question 13

oligohydramnios

Answer 13

• AFI <5cm or max pocket <3
• IUGR
• renal agenesis
• bladder neck obstruction
• fetal chromosomal abnormalities