OB

Question 1

Fetal Heart Tracing: HR & Variability

Answer 1

Normal HR: 110-160

Variability, normal amplitude of 6-25 bpm. Good variability assesses normal pH status, with reduced variability seen in fetal acidosis

Tachycardia:

• chronic fetal hypoxia - transient would be acute
• Fetal anemia
• Fever
• Chorioamnionitis
• Anticholinergic agents

Bradycardia:

• acute/subacute fetal hypoxia (MC cause)
• congenital heart block
• maternal beta blockers

Question 2

Fetal Heart Tracing: Decel’s

Answer 2

Early - Compression of head

Late - Uteroplacental insufficiency

Variable - cord compression

VEaL
CHoP

Question 3

Fetal Heart Tracing: Categories

Answer 3

Cat I: Normal tracing, good HR & variability, no decels, +accels

Cat II: Indeterminate zone, presence of reduced variability or bradycardia. Episodic decels. Closer monitoring required

Cat III: Sustained bradycardia, absence of variability, prolonged, consistent decels. Indicates poor fetus status, indicates urgent/stat c/s

Question 4

Preterm Fetal Assessment: Non-stress test

Answer 4

Monitors contractions & FHT over 20 minutes. Indicated for mothers with medical comorbidity, complication of pregnancy, or complication of fetus. Typically performed at 32-34 weeks.

Reactive: reassuring if 2 or greater accels during 20min, good variability. Accels will occur with movement and mom pushes button

Non-reactive: 0 or 1 accels during 20 min.

Question 5

Preterm Fetal Assessment: Biophysical Profile

Answer 5

Ultrasound examination with 5 different parts:

Cardiac: Assessment of HR, similar to FHT
Breathing: Looking for good breathing movement, more than 1 in 20 min period
Tone: Assess muscle tone, muscle movement
Amniotic Volume: Assessing for presence of renal hypoperfusion/decr in amniotic fluid volume

This test from 0 to 10 - if 0-2, mandates immediate delivery, 2-4 is likely antepartum admission. 8-10 is normal

Question 6

Intrapartum Fetal Assessment: Fetal scalp pH & SpO2

Answer 6

pH: normal >7.2

SpO2 30-70%

Scalp testing relative contraindications:

• Intact membranes
• Unengaged vertex
• Infections: HIV, HSV
• Fetal coagulopathy

Question 7

Meconium passage in utero

Answer 7

Meconium present in amniotic fluid can be indicator of fetal distress

Ultimately it reflects impaired clearance. Meconium stained fluid causes destruction/vascular damage which results in further impairment of transamniotic clearance.

Meconium can also cause umbilical vein contraction which results in fetal hypoperfusion/distress.

Question 8

Cerebral Palsy risks - peripartum period

Answer 8

Maternal mental retardation
Birth wt <2000g
Fetal malformation

Breech presentation
severe proteinuria during last trimester
third trimester bleeding
gest age <32wks

Question 9

Uterine blood flow Eq

Answer 9

UBF = (UAP-UVP)/Vascular resistance

Question 10

Amnio-infusion

Answer 10

Indicated for oligohydraminios - risk factor for cord compression.

Administer 800mL LR. Gravity is safer, can be c/b AFE

Question 11

Physiologic Changes of Pregnancy: Respiratory

Answer 11

Increase:

• Minute Ventilation
• Alveolar Ventilation
• Tidal Volume
• Oxygen consumption
• CO2 production

Decrease:

• Residual Volume
• ERV
• FRC
• PCO2