Some authors 1 suggest that continued moderate traction may aid in maintaining gained progress in descent of the fetal vertex. If the cup is dislodged, it is reapplied only after careful inspection of the fetal scalp for injury. 15 Traction is repeated with each contraction until the head is crowned. As the head clears the pubic symphysis, the vertex is pulled upward at an angle of 45 degrees to the floor. Once the head is delivered, suction is released, and the cup is removed.
Delivery then proceeds as usual.
15 Vacuum extraction should not be attempted for more than 20 minutes. The procedure should be abandoned if delivery is not achieved or the labor does not progress. Under ordinary circumstances, the procedure should be abandoned after three cup detachments. The procedure should also be stopped if there is any evidence of fetal scalp trauma. 8 Maternal and Fetal Complications Maternal complications associated with vacuum extraction are comparable to those associated with spontaneous deliveries.