Leading scientists say studies since then provide strong evidence that Plan B does not prevent implantation, and no proof that a newer type of pill, Ella, does. Some abortion opponents said they remain unconvinced.
Long-term birth control
methods work better than Pill
After The Times asked about this issue, A.D.A.M., the firm that writes medical entries for the National Institutes of Health Web site, deleted passages suggesting emergency contraceptives could disrupt implantation.