One can find studies which point to the risks of hormonal drugs used to regulate conception (contraceptives).
The latest is from July 2014 and it is written up in the Centers for Disease Control (CDC) website as “Preventing Chronic Disease | Association Between Contraceptive Use and Gestational Diabetes: Missouri Pregnancy Risk Assessment Monitoring System, 2007–2008,” found at http://www.cdc.gov/pcd/issues/2014/14_0059.htm…
as well as the more easily accessible (to the layman) UPI article,”Hormonal birth control linked with increased risk of gestational diabetes” (http://www.upi.com/Health_News/2014/07/17/Hormonal-contraceptives-increases-risk-of-gestational-diabetes/4611405632592/?spt=sec&or=hn).
Researchers who make the link between rising rates of breast cancer and the use of contraceptives include Joel Brin, Ph.D. and Angela DeFranchi, M.D. Their Breast Cancer Prevention Institute has many booklets and brochures that cite research and discuss ways to reduce the risk of contracting breast cancer (http://www.bcpinstitute.org/whys_of_breast_cancer_brochure.htm)