A recent open-label randomized controlled trial compared 436 women with Hb <10 g/dL at 13-26 weeks given 1 g intravenous ferric carboxymaltose against 432 women given 60 mg elemental iron [26]. The rate of anemia was numerically lower in the ferric carboxymaltose group than for those receiving oral iron at all subsequent gestational ages. Here, GSTM1 is linked to anemia.