“…The probability that a fetus has an echogenic bowel if the fetus is affected with CF, is a carrier, or is a noncarrier is estimated to be Ϸ 0.11, 0.00089, or 0.00035, respectively (using the data by Scotet et al 6 ). 5 Therefore, the probability that a fetus does not have echogenic bowel if the fetus is affected, a carrier, or a noncarrier is estimated to be 0.89 (ϭ 1 Ϫ 0.11), Ϸ1 (ϭ 1 Ϫ 0.00089), or Ϸ 1 (ϭ 1 Ϫ 0.00035), respectively. This means that a vast majority of pregnant CF carriers who undergo ultrasound examination will have negative results.…”