1. Department of Biostatistics (J.L.F.), University of Copenhagen, DK-1014 Copenhagen, Denmark
2. Departments of Clinical Biochemistry (T.H.J.), DK-2100 Copenhagen, Denmark
3. Growth and Reproduction (T.H.J.), Copenhagen University Hospital, Rigshospitalet, DK-2100 Copenhagen, Denmark
4. Fertility Clinic (J.G.B., A.P., E.C.L., A.N.A.), DK-2100 Copenhagen, Denmark