A device for measuring a length of a cervix includes an elongate measurement member, a hollow member, a flange, a handle, and a locking mechanism. The elongate measurement member extends along a longitudinal axis and includes a measurement scale thereon. The hollow member is coaxial with and disposed over the elongate measurement member. The flange is offset from the longitudinal axis and attached to a distal end of the hollow member. The handle is attached to a proximal end of the measurement member. The locking mechanism is configured, when locked, to fix the hollow member relative to the measurement member and, when unlocked to allow the hollow member to slide along the measurement member and rotate about the longitudinal axis so as to place the flange in a desired position without moving the measurement scale.