Which factor is associated with shoulder dystocia besides shoulder entrapment?

Shoulder dystocia is a birth complication that occurs when the baby's shoulder gets stuck after the head has been delivered, making it difficult for the rest of the body to emerge. While several factors can contribute to the risk of shoulder dystocia, precipitous births are particularly associated with this condition.

Precipitous births occur when labor progresses very quickly, typically defined as lasting less than three hours from the onset of contractions to delivery. This rapid delivery can result in the baby's body not having enough time to rotate properly during birth, increasing the risk of the shoulders becoming stuck behind the pelvic bone. The dynamics of a quick delivery may limit the natural movements necessary for a safe and proper exit of the fetus, thus heightening the risk of shoulder dystocia.

Other factors like prolonged labor, high maternal age, and multiple gestations can also be relevant, but they do not have the same direct association with shoulder dystocia as precipitous births do. Prolonged labor may lead to other complications, high maternal age could influence various factors related to pregnancy health, and multiple gestations may complicate labor dynamics, but the immediacy associated with precipitous births makes it a more significant risk factor in the context of shoulder dystocia.