LAUSR

A 31-year-old woman, gravida 2, para 0, was referred to our hospital at 28 weeks’ gestation for an enlarged biparietal diameter in the fetus. Her first pregnancy had ended in artificial abortion at 11 weeks’ gestation for social reasons. She did not have any histories including anorexia or coagulation abnormality. She began to vomit frequently at 7 weeks’ gestation and was treated for hyperemesis gravidarum with infusion of nutrients. The nutritional solution contained multiple vitamins but not vitamin K. Because severe vomiting persisted, detailed examinations were performed. Upper gastrointestinal endoscopy at 25 weeks’ gestation revealed reflux esophagitis. She also had a diagnosis of mental disorders (attention deficit/hyperactivity disorder and anxiety disorder), and on-demand use of a major tranquilizer (risperidone) was started. At 28 weeks’ gestation, an enlarged biparietal diameter was noticed, and she was referred and admitted to our hospital. Fetal sonography revealed an enlarged biparietal diameter of 85.5 mm (14.0 standard deviation [SD]) caused by bilateral subdural hematoma (Figure 1A). As maternal serum protein induced by vitamin K absence or antagonist II (PIVKA-II) concentration, which was induced in the liver as a result of vitamin K absence, turned out to be 1.391 mAU/m (normal,< 40 mAU/mL), we highly suspected vitamin K deficiency and started its replacement therapy. There were not any other abnormal findings such as thrombopenia and coagulopathy (eg, low fibrinogen levels) in the maternal