Change in risk status during labor in a large Norwegian obstetric department: a prospective study

This study aimed to observe risk status on admission to hospital and change in risk status during labor.

A prospective observational study allocating all women into low-risk and high-risk groups on admittance to hospital and during labor based on prespecified risk criteria.

Department of Obstetrics and Gynecology in a district hospital.

All 6406 deliveries from 2 May 2004 to 30 September 2006.

A special form was filled out for all women admitted to the department in labor classifying them as either low or high risk. A change in risk status during labor was also recorded.

Risk status (low and high risk) on admittance to hospital and change in risk status during first stage of labor.

On admittance, 67% of women with an intended vaginal delivery were low risk. During the first stage of labor, 41% of the low-risk women changed risk status. Use of epidural anesthesia gave rise to 73% of the risk changes during the first stage of labor and use of oxytocin caused 12%.

Two-thirds of the women were low risk before labor, and 39% of these remained low-risk at the end of the first stage of labor. The main reason for a change of risk status in the obstetric department was the use of epidural anesthesia.