Is slower than normal labor a symptom for a specific condition?

Longer labors. Longer labors are seen in some obstetrical conditions such as twins or larger babies. Longer labors are not associated with any specific medical conditions.
Increasingly common. Prolonged labors are increasingly common nowadays, as more women postpone childbearing until their late thirties or even forties, by which time their weight for height is typically increased. Prolonged labor is frequently a harbinger of cephalopelvic disproportion and cesarean section.