fetal complications of pregnancy Flashcards
what is SGA? LGA?
small for gestational age - < 10%ile
large for gestational age - > 90th %ile
how does an asymmetric SGA baby look?
torso & extremities are smalll but skull is normal.
what is decreased growth potential?
factors that result in SGA 2/2 congenital abnormalities, chromosomal disorders, intrauterine infections, teratogens.
what are the 2 most common teratogens causing SGA?
alcohol
cigarettes
what are the 2 phases of fetal growth?
hyperplasia before 20 weeks
hypertrophic after 20 weeks
an insult causing growth restriction prior to 20 weeks will most likely => what kind of growth restriction?
symmetric
asymmetric after 20 weeks
which is more common, asymmetric or symmetric IUGR?
asymmetric
what causes asymmetric IUGR?
decreased nutrition & o2 delivery to baby
IUGR can be caused by what 2 types of factors?
placental
maternal
any time a fundal height is _____ less than expected, an u/s s/b ordered to check fetal growth.
3 cm
how should umbilical a. flow look?
higher during systole but only drops by 50 to 80% during diastole.
Never any reversal of flow.
what is aspirin used for during pg’y?
low-dose aspirin c/b given in cases of SGA in moms w/a hx of placental insuff’y, preeclampsia, collagen vasc disorders, vascular dis
T or F: an SGA infant who has been small throughout pregnancy should be induced.
F. Only if fetal status is nonreassuring
how to manage SGA babies?
frequent NSTs, OCTs, BPPs, weekly u/s for growth monitoring, antenatal corticosteroids
what is macrosomia?
birth weight > 4.5kg
what is most common RF for macrosomia?
pregestational or gestational DM
other RFs for macrosomia?
maternal obesity postterm pg'y previous LGA maternal stature multiparity AMA male infant
mgt of LGA babies:
if GDM, control sugars well!
if obese mom, gain less weight (but don’t lose)
induce labor before macrosomia happens, maybe elective c/s, otherwise prepare for shoulder dystocia with vag delivery
LGA babies are at higher risk for what?
birth trauma hypoG jaundice lower Apgar scores childhood tumors
what is AFI?
amniotic fluid index, meas’d by u/s
< 5 is oligohydramnios
> 20 is polyhydramnios
what is the most common cause of oligohydraminos?
ROM
other causes of oligohydramnios?
renal agenesis
PCKD
GU system obstr’n
uteroplacental insuff’y
mgt of oligohydramnios:
if IUGR, obtain BPP, umb a. doppler flow, GA, find cause of IUGR.
Induce if at term.
refer to genetic counseling if congenital abnormalities.
if ROM at term but not in labor, induce.
Amnioinfusion if meconium present or frequent decels
which is mroe concerning, oligohydramnios or polyhydramnios?
oligo
what is polyhydramnios ass’d with?
congenital anomalies.
seen in pg’ies w/ DM, hydrops, multiple gestation
causes of polyhydramnios
GI tract obstruction
DM (increased G => osmotic diuresis)
hydrops 2/2 high-output HF
multiple gestation twin-twin transfusion syndrome
what m/b considered when doing an AROM in a pt w/ polyhydramnios?
only do it if head is truly engaged in pelvis, b/c increased risk of cord prolapse w/polyhydramnios
what is erythroblastosis fetalis (hydrops fetalis)?
when Rh- moms make antibodies against Rh+ fetal Ag’s that enter mom’s blood transplacentally and cause anemia in fetus.
nat hist of hydrops fetalis
heart failure, diffuse edema, ascites, pericardial effusion, jaundice, kernicterus
what to do for unsensitized Rh - pts?
draw an Ig screen at first prenatal visit. Give RhoGam at 28 weeks and postpartum if neonate is Rh+.
what to do for a sensitized Rh - pt?
draw antibody titers at initial visit and follow them q4weeks. If titer is < 1:16, expectant management. If > 1:16, do serial amnios to analyze fetal cells for Rh factor.
what to do if you have a sensitized Rh- mom, Rh+ baby detected on amnio?
serial amnios to eval for amt of biliriubin, indicating amt of hemolysis. Use Liley curve to predict severity of disease. If zone 3 of lLiley curve, do intrauterine transfusion
RhoGam should not only be given to Rh- women who are currently pregnant, but who else?
Rh- women who have miscarried, placental abruption, undergoing amniocentesis, or with ectopic pg’y
what can happen with a retained POC in intrauterine fetal demise?
if retained longer than 3-4weeks, hypofibrinogenemia, DIC
postterm pg’ies are at increased risk of what?
fetal demise
macrosomia
meconium aspiration
oligohydramnios
what is most common reason for postterm pg’y?
inaccurate dating
mgt of postterm pg’y:
NST at 41w
induce labor if non-reassuring fetal testing
NST and BPP at 42w
induce regardless if beyond week 42
how are monozygotic twins formed?
a fertilized ovum divides into 2 separate embryos
how are dizygotic twins formed?
mom ovulates 2 eggs
what is rate of twinning?
1 in 80
what is average GA for delivery of twins? triplets?
36-37
33-34
what is monochorionic?
one outer membrane
what is diamnionic
two amniotic sacs (inner membranes)
what is Mo-Di? Mo-Mo? Di-Di? Mo-Di?
Mo-Di = one outer mem, 2 amniotic sacs, each has own placenta but they can fuse. Can dvp twin-to-twin transfusion syndrome. Mo-Mo = one outer sac, one placenta, one amniotic sac. High mort rate 2/2 cord entanglement. Di-Di = zygote splits before diff'n of trophoblast => 2 chorion, 2 amnions. Mo-Di = embryo splits after diff'ation of trophoblast but before amnion formation => one placenta, one chorion, 2 amnions.
which form of twinning runs in famillies?
dizygotic
more common in African descent
what is twin-to-twin transfusion syndrome
unequal flow b/w vascular communications b/w twins with a shared placenta => one twin becomes donor and the other a recipient of the unequal blood flow
mgt of Mo-Mo twins:
frequent antenatal testing, early delivery via c/s
how can twins be delivered?
if vertex/vertex, trial of labor.
if vertex/nonvertex, trial of labor if presenting one is larger.
C/s if nonvertex/nonvertex
