[1] Acad Med Ctr, Dept Obstet & Gynaecol, Ctr Reprod Med, NL-1100 DD Amsterdam, Netherlands
[2] Free Univ Amsterdam, Med Ctr, Dept Obstet & Gynaecol, Amsterdam, Netherlands
[3] Hosp Univ Penn, Dept Obstet & Gynaecol, Philadelphia, PA 19104 USA
[4] Univ Aberdeen, Dept Obstet & Gynaecol, Aberdeen, Scotland
[5] Fertil & Reprod Endocrinol & Obstet & Gynecol, Philadelphia, PA USA
[6] Univ Med Ctr, Dept Reprod Med, Utrecht, Netherlands
[7] Univ Florida, Dept Hlth Affairs, Jacksonville, FL USA
[8] Columbia Univ, Mailman Sch Publ Hlth, Dept Epidemiol, New York, NY USA
[9] Univ Amsterdam, Acad Med Ctr, Dept Clin Epidemiol Biostat & Bioinformat, NL-1105 AZ Amsterdam, Netherlands