Which of the following is NOT a risk factor for shoulder dystocia?

High maternal age is not typically recognized as a direct risk factor for shoulder dystocia. The other factors listed have been shown to significantly increase the likelihood of experiencing shoulder dystocia during delivery.

Large fetal size, or macrosomia, is a well-established risk factor because larger infants are more likely to encounter difficulties during birth due to the increased chances of the shoulders becoming trapped behind the pubic bone. Maternal diabetes is also a notable risk factor since it often correlates with fetal macrosomia, leading to complications during delivery. Similarly, a previous history of shoulder dystocia is an important risk factor, as it indicates a higher chance of encountering the same situation in subsequent pregnancies due to structural or physiological changes that may predispose to reoccurrence.

In contrast, while maternal age can influence pregnancy outcomes, it doesn't have the same direct correlation with the incidence of shoulder dystocia as the other factors.