An absorbent article has longitudinal side edges, transversal end edges, and an absorbent core. The absorbent core comprises a first absorbent layer having an opening and a fluid flow control structure between said first absorbent layer and a backsheet. An elastic member is arranged along each longitudinal side edge. The first absorbent layer has a longitudinal front portion, a longitudinal back portion and a narrow transversal transition located between said front and back portions. The width of the narrow transversal transition is 50-75% of the widest transversal width of the front portion, and 20-50% of the longitudinal length of the opening is located in the front portion. The front portion constitutes 20-40% of the total longitudinal length of the first absorbent layer. An interspace is located in an area between the elastic member and the first absorbent layer at least in an area laterally outside the narrow transversal transition.