Sometimes women wonder if baby will flip head up, or breech, from doing an inversion.
I haven't heard of this happening to a head down baby when the pregnant woman does a short forward-leaning inversion.
There is no reason to do a longer inversion if baby is not breech. Repeating inversions more often is better than doing them for a long time.
Some women who do yoga will like to do yoga inversions for longer than 30 seconds. I don't know of a study showing whether "yoginis" (women who do yoga regularly) have a higher or lower rate of breech. I believe, but don't have the data, that pelvic and myo-fascial symmetry (muscle and fascia) reduces breech presentation. You decide what is best for you and consult a midwife or doctor to help you decide if you aren't sure. A hands-on abdominal exam will help determine whether your
abdomen is extra soft, roomy, or your uterus is holding enough extra water to let baby flip more easily than average. In average, babies don't flip easily.
You can ask your midwives and/or doctors if you have an unstable lie, high blood pressure, or polyhydramnios or any reason they can think of not to do a forward-leaning inversion.