A presenting part fetal pulse oximeter sensor with a securing mechanism for providing tension to a hook or other securing mechanism penetrating the fetal scalp. In one embodiment, a sensor can be secured to the presenting part of the fetus by means of a suture or a hook which penetrates the fetus' scalp. If a suture is used, the ends of the suture are wrapped around a securing member, such as a bar, attached to the back of the sensor. By tying the suture ends around this securing member, the sensor is pressed up against the fetus' scalp and retained in place by virtue of tension provided in the suture between the securing member and the portion of the suture penetrating the fetus' scalp.