In this episode of The Seasoned Sonographer, host Lynn Flamm, RDMS, dives into the third trimester ultrasound — from fetal measurements and fluid assessment to identifying fetal position and knowing when to add a Biophysical Profile (BPP). Lynn breaks down what sonographers need to document, common scan challenges, and why this late-pregnancy imaging can be both technically demanding and clinically critical. Then we’re joined by Certified Nurse Midwife Jessica Reichert, who shares how these ultrasounds impact care decisions from a provider’s perspective — and brings a powerful patient story that highlights just how much these scans can influence the course of delivery. This is a must-listen for sonographers, students, and OB providers navigating the final weeks of pregnancy care.
Topics Covered in This Episode:
When and why a third trimester ultrasound is ordered
Biometry: HC, BPD, AC, FL & how they’re used to estimate fetal weight (EFW)
Interpreting growth percentiles: SGA, FGR, macrosomia
Assessing fetal lie and presentation: cephalic vs. breech
AFI vs. SDP/MVP: how to evaluate amniotic fluid and what’s normal
Real-world scanning challenges: maternal habitus, fetal position, limited views
What to document when scans are technically limited
When to add a Biophysical Profile and what it tells us about fetal well-being
Special Guest: Jessica Reichert, CNM
Jessica shares how third trimester ultrasounds inform clinical judgment and patient care, especially in high-risk or borderline cases. She also discusses collaboration with sonographers and shares a powerful case that underscores why these scans matter.
Key Takeaway:
Ultrasound is a real-time, sonographer-dependent exam — and what we document (or can’t document) in the third trimester can significantly shape the final stages of pregnancy care.