1. Division of Reproductive Medicine (S.L.F., I.S., J.S.E.L.), Department of Obstetrics and Gynecology
2. Department of Internal Medicine (J.A.V., A.P.N.T., F.H.d.J.), 3000 CA Rotterdam, The Netherlands
3. Reproductive Endocrine Unit (C.K.W.), Massachusetts General Hospital, Boston, Massachusetts 02114
4. Department of Clinical Chemistry (Y.B.d.R.), 3000 CA Rotterdam, The Netherlands
5. Julius Center for Health Sciences and Primary Care (M.J.C.E.), 3508 GA Utrecht, The Netherlands
6. Division of Reproductive Medicine (F.J.B., B.C.J.M.F.), Department of Reproductive Medicine and Gynecology, University Medical Center Utrecht, 3508 GA Utrecht, The Netherlands
7. Division of Gynecological Oncology (E.M.R.), Department of Obstetrics and Gynecology, Erasmus Medical Center, University Medical Center, 3000 CA Rotterdam, The Netherlands
8. Department of Gastroenterology (W.H.M.P.), Radboud University Nijmegen Medical Center, 6500 HB Nijmegen, The Netherlands
9. Division of Endocrinology (A.C.S.H.-K.), Department of Pediatrics, Erasmus MC, Sophia Children's Hospital, 3000 CB Rotterdam, The Netherlands