Duchess of Cambridge 'unlikely to recover for several weeks' after pregnancy sickness worsens It tends to be a cycle of going into hospital, getting rehydrated, going home, getting dehydrated again because you're not getting intravenous fluids, and so on. The Duchess is still very ill by most people's standards and the chances of her going back to hospital are quite high. Mrs Dean, who suffered from hyperemesis with all three of her pregnancies, said the Duchess should "lie still in a dark room and just take it a day at a time, at the end of each day you know that's a day you don't have to do again." She added that the Duchess should tell her staff and family not to wear perfume and not to eat garlic, as the smell of either can bring on nausea, and added: "She is not going to be completely better by 12 weeks. It's a very slow progression and she may feel a lot better by the time she gets to 17 or 18 weeks, but it could carry on much longer than that. The Duchess is not yet 12 weeks pregnant, and hyperemesis is most common in the first three months of pregnancy. Despite feeling worse on Sunday, the Duchess has not required further hospital treatment and is continuing her recovery at home. The Duke and Duchess are both due to attend the Royal Film Performance of The Hobbit in Leicester Square on Wednesday night, but the Duchess's participation is highly doubtful. St James's Palace said today the Duke was still expected to attend the screening, but a decision on the Duchess's participation would be taken nearer the time.