A vacuum extractor for obstetrical use comprises a vacuum cup at one end of an elongated stem having a handle at the opposite end. The vacuum cup is sealed over a portion of the head of the fetus and a vacuum source, usually operating through the stem, connects to the inner side of the cup and secures it to the fetal head. A strain sensor is connected to the stem. When the force applied to the cup through the handle and stem exceeds a predetermined maximum, a valve connecting the vacuum pressure to the atmosphere is opened so as to release the vacuum pressure from the cup. Another extractor comprises an elongated hollow stem having one or more apertures along its length, a vacuum source connected to a cup supported on the stem, and a handle member which includes a traction limiting element operative to open and close the apertures.
