text: Use of mifepristone has been described but is rarely used in practice.
  Relaxin has been investigated, but is not currently commonly used.
  mnemonic; ARNOP: Antiprogesterone, relaxin, nitric oxide donors, oxytocin, prostaglandins
  Non-pharmaceutical
  Membrane sweep, also known as membrane stripping, Hamilton maneuver, or "stretch and sweep". The procedure is carried out by a midwife or doctor as part of an internal vaginal examination. The midwife or doctor puts a couple of lubricated, gloved fingers into the women's vagina and inserts their index finger into the opening of the cervix or neck of the womb. They then use a circular movement to try to separate the membranes of the amniotic sac, containing the baby, from the cervix. This action, which releases hormones called prostaglandins, may prepare the cervix for birth and may initiate labour. While this process causes great discomfort for the patient, even causing bleeding, irregular contractions and the risk of breaking the amniotic sack, many would still choose to have membrane sweeping carried out for their next birth.
  Artificial rupture of the membranes (AROM or ARM) ("breaking the waters")
  Extra-amniotic saline infusion (EASI), in which a Foley catheter is inserted into the cervix and the distal portion expanded to dilate it and to release prostaglandins.