Relationship of first-trimester subchorionic bleeding detected by color Doppler ultrasound to subchorionic fluid, clinical bleeding, and pregnancy outcome.

We analyzed retrospectively the incidence of subchorionic fluid and embryonic death in 2116 consecutive patients evaluated with abdominal ultrasound and 783 patients evaluated with vaginal ultrasound. These women were examined during the first 12 postmenstrual weeks and had conceived as a result of infertility treatment. In addition, we analyzed the relationship of subchorionic bleeding to subchorionic fluid in 230 patients evaluated with color Doppler ultrasound and the relationship of subchorionic bleeding to clinical bleeding, precipitating factors, pregnancy outcome, and the karyotypes of abortuses. In single gestational sac pregnancies, subchorionic fluid was found equally often in women scanned with vaginal or color Doppler ultrasound, and less often with abdominal ultrasound (P less than .0001). Embryonic death was increased only in patients with large amounts of subchorionic fluid observed on abdominal ultrasound. Color Doppler ultrasound revealed subchorionic bleeding in 87 of 235 ultrasound scans (37%) and in 48 of 102 patients (47%) when subchorionic fluid was present. Subchorionic bleeding was associated with moderate or large amounts of subchorionic fluid (P = .041), with precipitating events (P less than .0001), and with clinical bleeding (P = .001). It was occult in ten of 48 patients (21%). Embryonic death occurred equally often in women with no fluid and in those with subchorionic fluid, with and without subchorionic bleeding. Abortuses were karyotypically abnormal in an equal proportion of cases with subchorionic bleeding, subchorionic fluid, and no fluid. These findings indicate that subchorionic fluid and subchorionic bleeding are common findings in early pregnancy and are not associated with embryonic death unless they are accompanied by clinical bleeding.