Which maternal position has been shown to potentially decrease the likelihood of shoulder dystocia?

The choice of squatting or being on all fours is supported by evidence that these positions can help increase the available space in the pelvis and encourage optimal fetal positioning during labor and delivery. When a pregnant woman assumes a squatting position or kneels on all fours, the pelvic outlet expands, which may reduce the risk of shoulder dystocia. These positions can aid in repositioning the fetus and facilitate smoother delivery by allowing better gravitational assistance, thereby potentially minimizing complications like shoulder dystocia.

In contrast, lying supine can constrict the pelvic space and may hinder the progression of labor, increasing the risk of complications. Sitting upright can provide some benefits but does not enhance the pelvic dimensions as much as squatting or all-fours. Standing upright may offer advantages for certain stages of labor but lacks the specific biomechanical benefits that squatting or being on all fours provides in relation to reducing shoulder dystocia risk.