[Obstetric anesthesia/analgesia in Spain. Study notes on its historical evolution during the 1st half of this century].

This historical review of obstetric analgesia-anesthesia in Spain covers the first half of the twentieth century. Following usual practice for researching medical history, we have performed an exhaustive review of Spanish medical literature published during the study period, followed by classification, study and critical analysis. We found that the first half of the century saw considerable change in the application of analgesic-anesthetic techniques for childbirth and obstetric procedures, indicating that practitioners were far from apathetic as had been obstetricians of the second half of the nineteenth century, who generally rejected any type of analgesia for use during labor and birth. The numerous techniques in vogue during that period under study are described, although analgesia-anesthesia by inhaled ether and chloroform was undoubtedly the most widely used by obstetricians until well into the 1950's.