Indications for operative delivery between 1999-2010 and induction of labor and epidural analgesia on the risk of operative delivery--a population based Swedish register study

Objectives: The aim of this study was to describe the distribution of indications for vacuum extraction (VE) and emergency cesarean section (EMCS) from 1999 to 2010. Furthermore, we investigated the association of induction of labor and epidural analgesia (EA) on the risk of operative delivery.

Study design: Population based register study with data from the Swedish Medical Birth Register during 1999-2010 including all 415230 primiparous women giving birth in gestational week 37+0 to 41+6.

Main outcome measures: Indication for operative delivery as well as VE and EMCS.

Results: Among the VE deliveries the indication "signs of fetal distress" increased while "multiple indications" decreased. For EMCS, "prolonged labor" increased steadily while "multiple indications" decreased. The total rate of induction of labor increased from 8.2% in 1999 to 11.9% in 2010, and was associated with an increased risk of both EMCS (OR 3.37) and VE (OR 1.5). The total rate of EA increased from 43.7% in 1999 to 49.8% in 2010, and was associated with a double risk for VE (OR=2.23) and with an increased risk of EMCS (OR=1.64).

Conclusion: There have been changes in the distribution of indications for VE and EMCS during the study period. A growing number of mothers are being induced and more mothers receive EA. These factors seem to have influenced the rate of operative deliveries. Our findings underline the importance of carefully considering the advantages, disadvantages and risks with EA and induction of labor.