Under conditions where there is a risk of the uterine sound perforating a uterine wall, the uterine sound switches into an open position.

The open position provides an enlarged surface area of a distal end of the uterine sound that is in contact with a uterine wall and resists perforation by the uterine sound of the uterine wall.

A uterine sound is configured having an open and a closed position.

In one embodiment a uterine probe can include a transducer operative to emit sound waves for detection of a uterine contraction.

There is set forth herein a uterine probe having one or more transducer for detecting a uterine parameter.

The one or more parameter can be a fetal heart rate.

In one embodiment a uterine probe can include a transducer operative to emit sound waves for detection of a fetal heart rate (FHR).

Under normal operating conditions, the uterine sound is in the closed position for insertion into a uterus to measure the length of the uterus.

An alternative to the uterine sound is an endometrial aspirator such as those used for endometrial biopsy sampling.

A thin, rod-like instrument, called a uterine sound, may be inserted through the cervical opening to determine the length of the uterus.

A thin, rod-like instrument, called a uterine sound, may be inserted through the cervical opening to determine the length of the uterus and cervical canal.

Under conditions where there is a risk of the uterine sound perforating a uterine wall, the uterine sound switches into an open position.

The open position provides an enlarged surface area of a distal end of the uterine sound that is in contact with a uterine wall and resists perforation by the uterine sound of the uterine wall.

A uterine sound is configured having an open and a closed position.

In one embodiment a uterine probe can include a transducer operative to emit sound waves for detection of a uterine contraction.