Many mothers give birth in a lying-down position. This may have been adopted to make it more convenient for hospital staff to assist in labour and delivery, but may make labour more uncomfortable and difficult.
In some societies, childbirth is conducted in an upright postion (e.g., squatting, through use of a "birthing stool"). It is suggested that an upright position may help with childbirth because the pelvis can expand as the baby moves down. The weight of the womb is also less likely to press on mummy's major blood vessels that supply oxygen to the baby. The effect of gravity also helps the baby to move down the birth passage.
In a Cochrane review published in 2017 by Gupta et al., the authors suggested several benefits for an upright birthing position including a shorter duration of labour, reduction in the rates of episiotomy (a cut made in the vagina to allow the baby to pass through), and reduction in forceps-/vacuum-assisted deliveries.
Adoption of an upright birthing position may not be suitable for every mother. If you are not sure what is best for your childbirth, speak to your doctor to find out more.