Fetus and Newborn Flashcards
Define low birth weight
infant whose birth weight is < 2500 g
Define very low birth weight
Infant whose birth weight is < 1500 g
What are the percentiles for SGA, AGA and LGA?
SGA < 10%
LGA >90%
AGA between 10-90%
What is the definition of a preterm birth
born before the last day of the 37th week
What is the definition of a term birth
born between 38 and 42 weeks
What is the definition of post term birth
born after 42 weeks
What is the definition of perinatal death
death occurring between 28th week to 28th day of life
What maternal factors are most common in infants with higher mortality rates
women who delay prenatal care until after 1st trimester
teens
women > 40 years of age who did not complete high school
unmarried women
women with chronic disease (HTN, DM, autoimmune disease)
smokers
What type of infants have higher mortality rates?
boys
multiple births
preterm infants
What are the risk factors for prematurity?
previous abortion short interpregnancy interval assisted reproduction placental bleeding fetal distress erythroblastosis nonimmune hydrops uterine abnormalites tobacco use / substance use maternal chronic disease preeclampsia premature rupture of membranes chorioamnionitis bacterial vaginosis congenital abnormalities polyhydramnios Group B strep STD previous infant with SIDS incompetent cervix
What are some independent risk factors for increased mortality in pre-term infants?
male congenitial anomalies 5 minute apgar < 4 no antenatal steroids persistent bradycardia at 5 minutes hypothermia IUGR
What is the definition of IUGR
fetus is less than the 10th percentile for growth for gestational age
usually due to placental abnormalities or ischemic placental disease
What is the leading cause of infant death in the US?
congenital malformation, 25%
What is the appropriate number of vessels for an umbilical cord?
2 arteries and 1 vein
What is an abnormal number of umbilical vessels associated with and what should be checked?
most common is a single artery, 30% of these will have a congenital anomaly, trisomy 18 is the most common
consider renal US
What is chorioamnionitis and what should be done for an infant whose mother has chorioamnionitis?
maternal fever with or with out associated signs and symptoms of uterine tenderness, foul smelling amniotic fluid, maternal/fetal tachycardia
often follows prolonged rupture of membranes
infant should have culture and antibiotics even if infant is asymptomatic
In multiple gestations what sort of placentas and membranes can take place? What type of twins is each associated with?
monochorionic diamniotic: usually identical
dichorionic diamniotic: usually fraternal
What happens with the artery of one twin supplies a cotyledon that is then drained by the vein of the other twin
Twin twin transfusion
donor is very small and anemia
other twin is very large with polycythemia, possible CHF and hydrops
now a laser can be used to obliterate the connection
When is universal screening for GBS done?
Between 35-37 weeks
Who should receive intrapartum prophylaxis?
- mom delivered baby in the past with GBS disease
- Mom had GBS bacteriuria at any time during pregnancy
- Positive GBS screening result
- Unknown GBS status and
preterm labor
intrapartum temp > 100.4
rupture of membranes > 18 hours
intrapartum NAAT positive for GBS
What medication is given for GBS prophylaxis
penicillin G q 4 hours
if penicillin allergic:
and no anaphylaxis: cefazolin 2 g IV q 8 hours
If penicillin anaphylaxis: clindamycin if susceptible to both clinda and erythromycin
If not susceptible: vancomycin Ig q 8 hrs
What should be done to infants born of Mom who should get GBS prophylaxis?
Infant and mom must both be asymptomatic
If mom received prophylaxis -> observe infant for 48 hours
If mom did not receive prophylaxis (but should have), infant > 37 weeks, rupture of membranes < 18 hrs -> observe for 48 hours
or if < 37 week and rupture of membranes > 18 hours -> limited eval and observe for 48 hours
What are the confirmatory tests for premature rupture of membranes?
Check pH, 7-7.3 is consistent with amniotic fluid
check for ferning
What is the management for Premature rupture of membranes?
check lung maturity in those 32-39 weeks: lecithin / sphingomyelin ratio, phosphatidylglycerol level, lamellar body count
mature lungs will show twice as much lecithin to sphingomyelin
Delivery is recommended if lung maturity confirmed and infant > or equal to 34 weeks
if not, then expectant management with prophylactic antibiotics, steroids and tocolytics to delay labor