Objectives: To evaluate pain and other early adverse events associated with different regimens of medical abortion up to nine weeks of amenorrhoea.
Methods: The literature was searched for comparative studies of medical abortion using mifepristone followed by the prostaglandin analogue misoprostol. Publications, which included pain assessment were further analysed.
Results: Of the 1459 publications on medical abortion identified, only 23 comparative, prospective trials corresponded to the inclusion criteria. Patients in these studies received different dosages of mifepristone in combination with different dosages of misoprostol administered via diverse routes or at various intervals. Information on pain level was reported in 12/23 papers (52%), information regarding systematic administration of analgesics in 12/23 articles (52%) and information concerning analgesia used was available for only 10/23 studies (43%).
Conclusions: Neither pain nor its treatment are systematically reported in clinical trials of medical abortion; this shortcoming reflects a neglect of the individual pain perception. When data are mentioned, they are too inconsistent to allow for any comparison between different treatment protocols. Standardised evaluation of pain is needed and the correlation between the dosage of misoprostol and the intensity of pain must be assessed in future studies.
Keywords: Medical abortion; Misoprostol; Pain; Termination of pregnancy; Unwanted pregnancy.