[Relationship between epidural analgesia and type of delivery]

To study the relationship which exists between the administration of an epidural analgesic during labor and an instrument-aided, either with forceps or a suction cup, childbirth in the Teresa Herrera Maternity-Infant Care Hospital in A Coruña for the clinical cases studied during 1999.

380 cases were selected by lot by going through clinical files; of these 190 had received epidural analgesia while the other 190 had not.

Regarding isolated association between epidural analgesic usage and instrument-aided childbirth, we found that the risk of an instrument-aided childbirth is high (OR 2.7) when an epidural analgesic is administered. However, when we analyze our results weighing various factors which may cause confusion, we discover that if it is a woman's first birth, if the newborn's weight is greater than or equal to 3500 g and if an epidural analgesic is administered have an independent effect, in this order, on the presence of an instrument-aided childbirth. At the same time, this study showed a similar occurrence of cases of intra-labor fetal suffering for both groups (5.8% among childbirths in which epidural analgesia was administered and 5.3% among childbirths in which epidural analgesia was not administered); a statistically insignificant relationship (since is less than 0.05%).

The increase of an instrument-aided childbirth when an epidural analgesic is administered is due more to factors related to the aforementioned analgesia (such as first child birth, fetal weight greater than or equal to 3500 g or a tendency to shorten labor without fetal suffering,...) than to the analgesic itself. The impact of this on the latest developments in childbirth could be affected by a change in obstetrics practices.