Lumbar epidural analgesia in labour: relation to fetal malposition and instrumental delivery.

The incidence of instrumental delivery and malposition immediately before delivery was compared in patients who were given lumbar epidural analgesia and those who were not. Instrumental delivery was five times more common and a malposition of the fetal head was more than three times as common in the epidural group as in women who did not receive regional analgesia. Similar incidences were found even when the epidural was electively chosen before labour in the absence of medical indications. The instrumental delivery rate was affected by parity, the length of the second stage of labour, and the return of sensation by the second stage but not by other factors studied. The high incidence (20%) of malposition associated with epidural analgesia was not affected by any of the factors studied. The psychological and physical disadvantages of malposition and instrumental delivery have yet to be assessed. In the meantime, when there are no medical indications for epidural analgesia, the advantages of pain relief should be weighed against those of a normal spontaneous delivery.