Hb constant spring is a variant hemoglobin that affects α globin (a component of hemoglobin). This is a genetic problem (in other words, at least one of your parents is also a carrier of Hb CS, and you have a 50% chance to pass this problem on to the next generation), which is similar to α thalassemia, although not exactly the same. It's not a big problem for you, but for the sake of the next generation, your husband should thoroughly check whether he has alpha thalassemia. Whether his blood routine is normal or not, he should consider the genetic examination of thalassemia.