[1] Leeds Teaching Hosp, Leeds Ctr Reprod Med, Leeds LS14 6UH, W Yorkshire, England
[2] Monash Univ, Sch Publ Hlth & Prevent Med, Monash Ctr Hlth Res & Implementat, Monash Med Ctr, 43-51 Kanooka Grove, Clayton, Vic 3168, Australia
[3] Hammersmith Hosp, Inst Reprod & Dev Biol, London, England
[4] Penn State Coll Med, 500 Univ Dr,H103, Hershey, PA 17033 USA
[5] Univ Colombo, Fac Med, POB 271,Kynsey Rd, Colombo 008, Sri Lanka
[6] Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden
[7] Univ Med Ctr, Dept Reprod Med & Gynaecol, Heidelberglaan 100, NL-3584 CX Utrecht, Netherlands
[8] Univ Adelaide, Robinson Inst, Norwich House,55 King William St, Adelaide, SA 5005, Australia