Table 1 Comparison of gestational age estimates using cfRNA and ultrasound.

Distribution of difference between estimates of gestational age, which assume delivery at 40 weeks gestation, and observed gestational age at delivery listed for four distinct methods, where n indicates the number of women included. Gestational age was estimated using cfRNA measurements from the second (T2), third (T3), or both (T2 and T3) trimesters and ultrasound measurements from the first trimester (T1).

MethodΔ [observed – expected delivery date (weeks)] (%)
< –2–1 to –2± 1+1 to +2> +2
cfRNA (T2, n = 28)50183200
cfRNA (T3, n = 31)06232942
cfRNA (T2 and T3, n = 31)196451020
Ultrasound (T1, n = 31)02648233