At what point should embryonic cardiac activity be detected on Ultrasound

At what point should embryonic cardiac activity be detected on Ultrasound?

Embryonic cardiac activity is usually visible as soon as an embryo is detectable sonographically, often at a CRL as small as 2 mm.

The absence of sonographically detectable embryonic cardiac activity by a CRL ≥7 mm is diagnostic of a failed pregnancy, as is the absence of an embryo with a heartbeat ≥2 weeks after an US examination demonstrates a gestational sac without a yolk sac, and absence of an embryo with a heartbeat ≥11 days after an US demonstrating a gestational sac with a yolk sac.

Between 5 and 8 weeks, the embryonic heart rate is usually 100 beats/min or greater. From 8 weeks to term, the average heart rate is 140 beats/min (range 120 to 180 beats/min). The thresholds for bradycardia based on embryonic size are listed in the below table.

Thresholds for Bradycardia Based on Embryonic Size

CROWN RUMP LENGTH (MM)BRADYCARDIA (BEATS PER MINUTE)
<5<80 bpm
5-9<100 bpm
10-15<110 bpm
15585

Sign up to receive the trending updates and tons of Health Tips

Join SeekhealthZ and never miss the latest health information

15856