As a physician, I would discourage a woman in labor from calling an ambulance to go to the hospital, as the ambulance may be needed for a true pikuach nefesh emergency such as a cardiac arrest, stroke, etc., and the woman would be better served to arrange a taxi or service drive her. Thank you for your attention.

Shalom U'verachah, Thank you for this observation, however we do see that ambulances are used for this purpose and sometimes it is critical as the birth is so advanced that the woman needs medical attention before she arrives in the hospital. Kol Tuv