1. Department of Endocrinology (B.V., B.S.), Peninsula Medical School, Royal Devon & Exeter Hospital, Exeter EX2 5DW, United Kingdom;
2. Departments of Endocrinology (S.A., M.B., R.B.), James Cook University Hospital, Middlesbrough TS4 3BW, United Kingdom
3. Clinical Biochemistry (J.D.), James Cook University Hospital, Middlesbrough TS4 3BW, United Kingdom
4. Obstetrics (S.H.), James Cook University Hospital, Middlesbrough TS4 3BW, United Kingdom