The breathing techniques that you can use during pregnancy and labor go far beyond "hee-hee-who." The APA highlights several different methods, including:
The organizing breath. This is how you should begin every breathing pattern. Inhale deeply, and exhale with a big sigh. This will increase focus and release tension.
Slow breathing. This technique is pretty much what it sounds like: Inhale slowly through the nose, and exhale through your mouth. Be patient, and take the next breath when you're ready. This type of breathing helps manage contraction pain.
Light accelerated breathing. This is a faster pattern than involves taking rapid, shallow breaths through the mouth at a rate of about one breath per second. During labor, the pace should increase as the contraction intensifies and decrease as it slows down.
Variable or transition breathing. This is the popular "hee-hee-who" or "pant-pant-blow" technique, where you breathe in lightly, taking shallow inhalations, and breathe out with long, relaxing exhalations.
Expulsion breathing. This technique is guided by the contraction: The mother speeds up and lightens her breathing as she's comfortable until she can no longer resist the urge to push. She then takes a deep breath, leans forward, and breathes out with a moan or grunt.