PLACENTAL SITE CORD INSERTION

NORMAL CORD INSERTION

• Cord insertion is 1-2 cm from the placental edge (1,2)

ABNORMAL CORD INSERTION

• Defined as insertion of the cord within 1cm (1) or 2cm of the placental edge (2).
• There is a high specificity (95%) but a low sensitivity (42%) for prenatal identification of an abnormal cord insertion site (2).
• Color doppler imaging may increase the sensitivity and specificity to 69% and 100% respectively (1). Positive predictive value was 100%.

REFERENCES

1. Di Salvo DN, Benson CB, Laing FC et.al. Sonographic evaluation of placental cord insertion site. AJR 1998;170:1295-1298.
2. Pretorius DH, Chau C, Poeltler DM et.al. Placental cord insertion visualization with prenatal sonography. J Ultrasound Med 1996;15:585-593.