Xenia C., I never heard of hyperemesis gravidus before I had it (I'm spelling it differently than most here, but that's the way the doctors spelled it when I had it).
I had heard of morning sickness which was tolerable and confined largely to the mornings. I kept expecting it to leave, but it didn't, and I was stick thin when I finally went to the obstetrician, who put me in the hospital with a diagnosis immediately. It did not hurt my baby, apparently, as he was large and healthy and very intelligent. However, I did begin recovery at three months and was pretty well over it by three months and three weeks.
I realize now that the hormone changes triggered my genetic disease Porphyria, but no one then suspected it. The fact that I had porphyria was one reason I responded so dramatically to glucose infusion, and even could eat solid food while on glucose infusion; glucose is a standard treatment for porphyria attacks. If I had been on a daily glucose infusion I might have gotten well much quicker. Since I could keep almost nothing down, including pills, I could not have eaten sufficient sugar to equal the glucose; yet, if I had known, I would have tried to eat more pure sugar, which would have been contrary to my nutritional training at home, and which would have seemed ludicrous. I remember how well I felt on the glucose IV in the hospital, and I regained cheerfulness and hope. The doctor said I looked "green" and he hoped I would have twins and then quit childbearing.
I would start to vomit within hours of going off the glucose iV.
Makes one wonder if Kate will assay a second pregnancy, if her condition goes on too long and wears her down too much.