7: Fetal complications Flashcards
if fundal height varies more than ? from gestational age, get US
3 cm
conditions that lead to SGA infants
congenital: Down’s, trisomy 18, 13, Turner syndrome, OI, achondroplasia, NTDs, anencephaly, other AR diseases
IU infection: CMV, rubella
exposure to teratogens (etOH, cigarettes)
radiation exposure
small maternal stature
maternal risk factors for IUGR
HTN, anemia, CKD, SLE, APA syndrome, malnutrition, severe DM
placental risk factors for IUGR
placenta previa, chronic abruption, placental infaction, multiple gestations, placental thrombosis, marginal cord insertion
how to monitor infant at risk for IUGR
serial US scans every 2-3 wks
fetus with DGP will be consistently small, whereas IUGR will progressively fall off the growth curve
another test to ddx IUGR
doppler investigations of the umbilical artery
normally diastolic flow decreases to 50-80% of systolic, but if significantly decreased or even reversed/absent implies increased placental resistance (thrombosed/calcified placenta)
fetal demise risk assessment of SGA fetuses that have fallen off growth curve
nonstress test (NST), oxytocin challenge test (OCT), biophysical profile (BPP), and umbilical Doppler velocimetry
definition of macrosomia
a birth weight greater than 4,500 g
risks of macrosomia
low Apgar scores, hypoglycemia, polycythemia, hypocalcemia, and jaundice.
leukemia, Wilms tumor, and osteosarcoma.
offer elective C section at what fetal weights?
estimated fetal weight of 5,000 gms or greater in women without gestational diabetes and 4,500 gms or greater in women with gestational diabetes.
The amniotic fluid reaches its maximum volume of about ? at about ? weeks.
800 mL at about 28 weeks
volume maintained until close to term when it begins to fall to about 500 mL at week 40
how is amniotic fluid index (AFI) calculated
by dividing the maternal abdomen into quadrants, measuring the largest vertical pocket of fluid in each quadrant in centimeters, and summing them
oligohydramnios?
polyhydramnios?
AFI less than 5
AFI 20 or 25+
oligohydramnios risks
umbilical cord compression, congenital anomalies (GU), IUGR
causes of oligohydramnios
ROM is most common!
chronic uteroplacental insufficiency (UPI), Congenital abnormalities of the GU tracts, Potter syndrome (renal agenesis), PKD, obstruction of GU system
polyhydramnios associations
Fetal structural and chromosomal abnormalities, maternal DM, NTDs, obstruction of fetal alimentary canal, hydrous, TE fistula, duodenal atresia, twin-twin transfusion
Erythroblastosis fetalis, or fetal hydrops s/s
hyperdynamic state, heart failure, diffuse edema, ascites, and pericardial effusion, is the result of serious anemia. Fetal hydrops is defined as accumulation of fluid in the extracellular space in at least two body compartments.
when should RhoGAM be given?
to Rh- mother at 28 weeks and postpartum if the neonate is Rh+
also if exposed to fetal blood: amniocentesis, miscarriage, vaginal bleeding, abruption, and delivery
0.3 mg of Rh IgG, will eradicate 15 mL of fetal RBCs
if Rh Ab screen is +, check Ab titers. what is a worrisome titer? f/u with what?
> 1:16
-begin serial amniocentesis at 16-20 wks to determine fetal Rh status
if fetus is Rh+ in sensitized mom with titers >1:16 check for ?
fetal anemia using fetal middle cerebral artery (MCA) Doppler measurements, will have greater PSV (peak systolic velocity) measurements
beneficial procedures for fetal anemia
percutaneous umbilical blood sampling (PUBS) and intrauterine transfusion (IUT) next best: fetal intraperitoneal transfusion
other RBC antigens
ABO blood type, antigens CDE in which D is the Rh antigen, Kell, Duffy, and Lewis
a retained IUFD > 3 to 4 weeks can lead to
hypofibrinogenemia secondary to the release of thromboplastic substances from the decomposing fetus–>DIC
treatment for early IUFD
evacuation with D/E or with mifepristone and misoprostol
treatment for IUFD >20 wks
the pregnancy is usually terminated by induction of labor with prostaglandins or high-dose oxytocin
screening tests to do after IUFD
screening for collagen vascular disease or hypercoagulable state, fetal karyotype, and often TORCH titers (i.e., toxoplasmosis, RPR, CMV, and HSV).
microarray studies of the fetal or placental genome to both look for aneuploidy, autopsy
postterm pregnancy
fetal associations?
> 42 weeks
anencephaly, fetal adrenal hypoplasia, and absent fetal pituitary. All are notable for diminished levels of circulating estrogens.
most clinicians offer induction after ? weeks
benefits?
> 41 wks
lower rates of cesarean delivery (even with an unfavorable cervix) as well as lower rates of meconium aspiration syndrome
Recent evidence suggests that active labor does not begin until at least ?cm in induced labor.
6cm
obstetric complications of multiple gestations
preterm labor, placenta previa, cord prolapse, postpartum hemorrhage, cervical incompetence, gestational diabetes, and preeclampsia
multiple gestation fetus is at risk for
preterm delivery, congenital abnormalities, SGA, and malpresentation.
Monochorionic (one placenta), diamnionic (two amniotic sacs) (Mo-Di) twins are at risk for ?
twin-to-twin transfusion syndrome (TTTS) as they often have placental vascular communications
Monochorionic, monoamnionic (Mo-Mo) twins complications
an extremely high mortality rate (reported as high as 40% to 60%) secondary to cord accidents from entanglement.
Di-Di twins if division before
Mo-Di twins if division btw
Mo-Mo twins if division btw
day 3 days 3-8 days 8-13 days 13-15 after will be single
“twin peak” sign seen on US
in Di-Di twins: the fused chorionic and amniotic membranes
Twin-to-Twin Transfusion Syndrome (TTTS) or Polyhydramnios-oligohydramnios (poly-oli) sequence results in
one fetus with hypervolemia, cardiomegaly, glomerulotubal hypertrophy, edema, and ascites, and the other with hypovolemia, growth restriction, and oligohydramnios.
Vaginal delivery of ? presenting twins is preferred and is possible with ? twins under the right circumstances. ? presenting twins are delivered by cesarean section.
vertex/vertex
vertex/nonvertex
Nonvertex
