A 27-year-old primipara presents at 12 weeks of gestation with recurrent, severe nausea and vomiting. She is also lethargic and weak. She was diagnosed with hyperemesis gravidarum two weeks ago, which was managed with IV fluids and anti-emetics. No underlying medical disorders were detected. An ultrasound scan at that time showed a single live intrauterine gestation of 10 weeks. A full blood count is found to be normal.