“Pieces of a Woman” is a movie that is difficult to review, and, at times, difficult to watch. But if anyone will remember it, it would be for its long opening sequence of a woman giving birth. It’s an incredible scene, fiercely acted by Vanessa Kirby, who truly gives a sensational performance here. As you might have guessed, the scene ends with the death of the newborn, which sets the tone for the rest of this drama. And so begins “Pieces of a Woman”, a film about grief that doesn’t always hit all the right notes, but still manages to hit you where it hurts the most. I could swear that there were times where I would simply look away, only to be sucked in once again by Kirby’s terrific acting. Kirby is also surrounded by a first rate cast that includes Shia LaBeaouf, Ellen Burstyn and Molly Parker. Hungarian director Kornél Mundruczó builds his film slowly and deliberately, before offering a catharsis that ultimately makes the often harrowing drama worthwhile.