[1] Univ New S Wales, Sch Womens & Childrens Hlth, Natl Perinatal Epidemiol & Stat Unit, Sydney, NSW 2031, Australia
[2] Royal Hosp Women, Sch Womens & Childrens Hlth, Sydney, NSW, Australia
[3] IVF Australia, Sydney, NSW, Australia
[4] Saitama Med Univ, Fac Med, Dept Obstet & Gynecol, Moroyama, Saitama, Japan
[5] Univ Diego Portales, Santiago, Chile
[6] Univ Diego Portales, Program Eth & Publ Policies, Santiago, Chile
[7] Karolinska Inst, Inst Med Epidemiol & Biostat, Stockholm, Sweden
[8] Palo Alto Med Fdn Fertil Physicians Northern Cali, Palo Alto, CA USA
[9] Stanford Univ, Stanford Univ, Dept Gynecol & Obstet, Stanford, CA 94305 USA
[10] Univ Calif San Francisco, Dept Obstet Gynecol & Reprod Sci, San Francisco, CA 94143 USA