Researchers study breast cancers after pregnancy

Christina Miller talks about her battle with breast cancer.

Christina Miller and her children Alex, 5, and T.J., 4.

Christina Miller cleans up after making lunch for her three children.

Christina Miller, 39, receives a herceptin infusion as part of her breast cancer treatment at Georgetown's Lombardi Cancer Center in Washington, D.C. She was diagnosed in January.

Christina Miller heads down to the basement with daughters Nora, 17 months, and Alex, 5.

Christina Miller's daughter Nora, 17 months, plays with a lace curtain.

Christina Miller plays with children Nora, 17 months, T.J., 4, and Alex, 5. Miller was diagnosed with breast cancer right after Nora's birth.

Christine Miller plays with her children Alex, 5, T.J., 4, and Nora, 17 months.

Christina Miller, 39, plays with her son TJ, 4, at a park in Bethesda, Md.

Christine Miller changes a diaper for daughter Nora.

Christine Miller kisses her youngest daughter Nora.