Snapshot A 35-year-old woman at 42 weeks of gestation presents for an induction of labor due to postterm pregnancy. She reports positive fetal movement, and denies vaginal bleeding. After amniotomy is performed, a change in the fetal heart rate is noted, as seen in the tracing in the image. Maternal repositioning is performed. (Variable decelerations) Introduction Overview intrapartum fetal assessments are performed to assess fetal well-being during labor and delivery biophysical profile (BPP) fetal heart rate (FHR) monitoring electronic fetal monitoring (EFM) is the most common method to assess the fetus during labor Biophysical Profile (BPP) Five measurements of fetal well being, each rated on scale of 0 or 2 measurements fetal breathing gross body movements fetal tone extremity extension and flexion amniotic fluid volume nonstress test (NST) Scoring 8-10 is reassuring 6 is equivocal delivery if > 36 weeks repeat BPP in 24 hours if < 36 weeks ≤ 4 is abnormal requires immediate intervention, prompt delivery Fetal Heart Rate (FHR) Normal FHR 120-160/min Tachycardia is FHR > 160/min causes include maternal fever fetal hypoxia prematurity anemia (maternal or fetal) chorioamnionitis hyperthyroidism Bradycardia is FHR < 110/min for > 10 minutes causes include congenital heart block maternal β-blockers FHR variability reliable indicator of fetal well being causes of decreased variability include fetal hypoxia congenital heart anomalies Electronic Fetal Heart Rate Monitoring (EFM) Tracing Interpretation Accelerations ↑ FHR at least 15/min above baseline for ≥ 15 seconds and < 2 minutes in a 20 minute period when gestational age is > 32 weeks or 10/min for ≥ 10 seconds when gestational age is < 32 weeks considered a reactive NST (needs the presence of at least 2 accelerations) suggests fetal well being if this was a NST during pregnancy (not intrapartum), management would be routine-follow-up Early decelerations ↓ FHR (not below 100/min) that coincide with uterine contraction nadir of the deceleration meets the apex of the uterine contraction results from pressure on fetal head (fetal head compression) resulting in vagus nerve stimulation and reflex bradycardia physiologic and not harmful to fetus Variable decelerations may not coincide with uterine contractions rapid ↓ in FHR (often < 100/min) with variable recovery reflex mechanism due to umbilical cord compression rupture of membrane can lead to umbilical artery compression correct by shifting maternal position or amnioinfusion if membranes ruptured considered first-line if maternal repositioning does not improve FHR tracing, amnioinfusion can be considered Late decelerations begins after uterine contraction has started associated with uteroplacental insufficiency and viewed as potentially dangerous potential causes placental abruption maternal diabetes maternal anemia maternal sepsis postterm pregnancy hyperstimulated uterus repetitive late develerations require intervention Sinusoidal tracing sine-wave like pattern associated with increased morbidity and mortality indicative of severe fetal anemia e.g., severe hypoxia and Rh disease