intrapartum care Flashcards
testing and tx of GBS
Test all women in clinic with a vaginal and rectal swab at 35-37 weeks
2. Women who test positive are not treated prenatally
Offer prophylactic antibiotics in labor to decrease the rate of transmission to the baby
PCN G 5 million units IV loading dose then 2.5 mil units q 4hrs until delivery
b. Ampicillin 2 grams IV, then I gram IV q 4 hours as second choice, “four hours before delivery”
transmission of GBS
70% rate of vertical transmission to fetus once membranes rupture
MCC of neonatal sepsis
- Babies have respiratory symptoms that resemble RDS
2. Can cause meningitis and pneumonia as well
The most common cause of neonatal sepsis
GBS
sxs of GBS
Asymptomatic in women, though some may have GBS induced UTIs
- If UTI discovered prenatally treat with antibiotics and note in chart
a. Will get GBS prophylaxis in labor
monitoring in labor
- Maternal Vitals
- Contraction frequency, duration, strength by palpation
- Fetal heart rate by EFM (electronic external fetal monitor) or intermittent Doppler
- Confirm status of membranes, uterine bleeding
- Cervical dilatation, effacement and station
- Presentation and position (anterior, posterior or transverse) of fetus
- EFW (estimated fetal weight) – not done as much now
how do you measure effacement
shortening of cervix (measured in percentage)
i. 0% - long hard 3cm cervix
ii. 100% - completely thinned out like a sheet
what is meant by the phrase cervicle station
– where baby is in relation to the ischial spine
PPROM
Antenatally/preterm (preterm premature rupture of membranes (PPROM)) <37 wks
PROM
At term but before the onset of labor (premature rupture of membranes (PROM))
SROM
iii. Spontaneously at onset of or during labor (SROM)
AROM
Via practitioner (amniotomy or artificial rupture of membranes (AROM))
done with amni hook; can help the labor along if done at the right time
Indications for antibiotic prophylaxis for GBS
Positive screening cx for GBS (vagina or rectum)
Positive hx of birth of an infant with early-onset GBS disease
GBS bacteriuria during current pregnancy
Unknown antepartum culture status AND
Intrapartum fever >100.4F or
Preterm labor < 37 weeks, or
Prolonged ROM >18 hours or
chemoprophylaxis for GBS has reduced disease by
- Maternal intrapartum GBS chemoprophylaxis has resulted in a significant reduction in early onset GBS disease (>80% of cases)
Meconium staining
Term or post term fetuses are developmentally able to move their bowels and may do so spontaneously causing meconium stained fluid
Stressed/hypoxic baby will also pass meconium
3. Occurs about 20% of the time
meconium what is it and how is it created
Thick, black-green, odorless material first demonstrable in the fetal intestine during the third month of gestation
Results from the accumulation of debris (desquamated cells from the intestine/skin, GI mucin, lanugo hair, fatty material from vernix caseosa), amniotic fluid, intestinal secretions, and bile pigments.
what is the issue with meconium
, but if breathed into the lungs it may stimulate the release of cytokines/vasoactive substances leading to cardiovascular and inflammatory responses in the fetus/newborn
if light meconium
- If light meconium, expectant management, amnioinfusion? (putting a catheter with saline into the cervix and help wash it out during labor
- Thick or dark meconium requires
peds notification (usually means its happened recently)
Will probably desire suctioning the nares/mouth immediately after delivery of head, before delivery of body
Will prepare for possible intubation immediately after delivery to visualize below the vocal cords for meconium aspiration
how common and who is greatest risk for meconium aspiration
a. Occurs 2-10% of infants born through meconium stained fluid
b. Greatest risk in postmature infants and SGA infants
outcomes of meconium aspiration
c. Meconium causes mechanical obstruction (doesn’t allow the lungs to expand) and chemical pneumonitis leading to serious pulmonary hypertension
Frequently fatal
rational for FHR
FHR patterns are indirect markers of the fetal cardiac and medullary responses to blood volume changes, acidemia, and hypoxemia
EFM vs ausculation fetal monitoring
Continuous EFM was associated with an extra 12 caesarean sections, and 25 operative (assisted) deliveries per 1000 births
what are Accelerations
“Accels” - a reassuring indicator of fetal well-being (fetus NOT acidotic)
what are normal accels
Baseline FHR 110-160bpm
Moderate variability is reassuring
c. May be absent due to sleep
EFM
Electronic fetal monitoring (EFM
v
early decels indicate
– happen during height of contraction and they mirror the contraction
- Happen d/t head compression
- Not concerning as long as they return to baseline
benign
variable decels indicate
– steep decels happen in line with the uterine contraction and returns to baseline as soon as the contraction is over
1. Happen d/t cord compression
benign
late decels
NOT BENIGN
happening after the zenith of the uterine contraction
1. Sign of uteroplacental insufficiency – baby is not getting enough O2
get FBG to monitor pH
waht are decels
periodic FHR changes associated with UCs (uterine contractions)
how does fetal electrocardiogram work
— bipolar spiral electrode inserted into fetal scalp/second reference electrode is placed upon the maternal thigh to eliminate electrical interference.
b. Detects fetal ECG) and calculates the FHR
what to do with non reassuring patterns
Call for assistance
Administer O2 via tight fitting mask
Change maternal position (lateral or knees/chest
Administer fluid bolus (lactated Ringer’s)
Perform vaginal exam, fetal scalp stimulation
Consider tocolysis for uterine tetany or hyperstimulation
Discontinue oxytocin if used
Consider amnioinfusion (for variable decels)
Determine if operative intervention is warranted/how urgently
VAS
ix. Vibroacoustic Stimulation (VAS) – artificial horn
- Startles baby - Should ellicit accels
- Procedure stimulates the fetus to move, shortening the duration of time needed to produce an acceleration, without compromising the predictive value of a reactive NST.
fetal surveillance looks like what before birth
i. Goal is to identify fetus at risk of intrauterine death/asphyxia
ii. PMH, family hx, genetic hx, psychosocial hx will all help identify risk factors
iii. Indications for testing include, GDM, HTN/preeclampsia, multiple gestation, decreased fetal movement, hx of prior stillbirth, increased risk for stillbirth, postdates pregnancy, amniotic fluid abnormalities, fetal growth restriction
iv. Fetal movement (FM) awareness, “kick counts”
v. FHR, variability
vi. Uterine growth
when should fetal movement be palpable and when would we worry
Palpable movement 17-20 weeks “quickening”,
fetal movement decreases in response to hypoxia
Amniotic Fluid Analysis
what is ti and what does it look like
Amnio or vaginal if ROM) – Testing to determine pulmonary maturity: i.
-Biochemical tests and biophysical tests
most useful marker with a fetal surveillance sonogram
ii. Nuchal translucency 10-14 wks – most useful marker (trisomy 21), Turners, heart defects, cystic hygroma (may be concerned with trisomy or monosomy X), single umbilical artery
on anatomic scan you are looking for
looking at femur length, CRL, biparietal diameter
how often are abnormal U/S markers associated with normal fetus
vi. Abnormal U/S markers can be associated with normal fetuses and should be correlated with prenatal diagnostic testing. Isolated “soft” markers are identified in 11-17% of normal fetuses
what are soft markers
vii. “Soft” markers include: Increased nuchal translucency, absent nasal bone, echogenic bowel, pyelectasis, shortened long bones, echogenic intracardiac focus.
Most common cardiotocographic method of antepartum fetal assessment.
Nonstress test (NST)
Most common cardiotocographic method of antepartum fetal assessment. There are no direct maternal or fetal risks from nonstress testing – does not require oxytocin or contractions
what is the false postive false negative rates for non-stress test
- Higher rates of FN (false negatives) and FP (false positive) rates than CST
non-stress test that is reactive means
“Reactive” meets or exceeds criteria
- “Nonreactive” is nonreassuring finding
non reactive non-stress tests warrants
Nonreactive or inconclusive usually requires f/u w/ BPP or contraction stress test (CST)
Most accurate predictor of uteroplacental insufficiency
CST (contraction stress test)
Most accurate predictor of uteroplacental insufficiency – a hypoxic fetus will demonstrate recurrent late decels
Contraction stress test (CST)-when can it be done
)More expensive, takes more time, high false positives
Can be used from 26 weeks on
Used to f/u on NST
how do you administer CST
- Uses oxytocin (pitocin) or nipple stimulation to create uterine contractions
- Criteria: 3 UCs/10 min, felt or not
CST
Negative (good): FHR stable, no late decels
Positive (bad): repetitive late decels with each UC
Equivocal: unable to obtain satisfactory tracing
few false negative many false positives
when do we do a BPP
Combined with electronic fetal monitoring nonstress test (NST)
Fully oxygenated fetus that is neurologically intact will demonstrate what with a BPP
a. Muscle tone
b. Gross movement
c. Respiratory activity
d. And will have:
i. An adequate AFI
ii. A reactive NST
e. >8 = reassuring
what is happening in Rh isoimmunization
Red cells of the fetus or newborn are destroyed by maternally-derived alloantibodies
how does rhogam work
Passive immunity
wears off in a few weeks and antibodies will decline to 0
when is rhogam NOT given
Not given to women who are already D alloimmunized, or biologic father CONFIRMED to be Rh Negative, consider genetic counseling
when do we do AB screen
AB screen at first prenatal visit
AB screen again at 28 weeks, Prophylaxis at 28 weeks
when do we give rhogam
After possible placental trauma, SAB, induced abortion, invasive prenatal diagnostics, ectopic, TAB, fetal demise, molar pregnancy
v. Within 72 hours post partum of delivery of D-positive newborn
erythroblastis fetalis
Alloimmune hemolytic disease of the newborn (HDN) aka erythroblastis fetalis (when it is of the fetus)
Clinical manifestations of alloimmune HDN
range from mild, self-limited hemolytic disease (eg, hyperbilirubinemia with mild to moderate anemia) to severe life-threatening anemia (eg, hydrops fetalis).
Less severely affected infants with HDN typically present with
Hyperbilirubinemia — Less severely affected infants typically present with unexpected hyperbilirubinemia within the first 24 hours of life.
anemia in HDN
k. The degree of anemia varies depending upon type of HDN (hemolytic disease of newborn)
l. Some infants with Rh or some minor blood group incompatibilities can present with symptomatic anemia that require RBC transfusion.
when do we see hydrops fetalis
Infants present with skin edema, pleural/pericardial effusion, or ascites.
Infants with Rh(D) and some minor blood group incompatibilities, such as Kell (most immunogenic antigens after Rh and ABO blood group systems), are at risk for hydrops.
ii. Neonates with hydrops may present at delivery with shock/ require emergent transfusion.
which antigens are crossing the placenta
Antigens that cause IgM antibodies
1. Cannot cross placental barrier (they are too big), only IgG
what types of antibodies cross the placenta
