Chelsea Clinton announces second pregnancy on Twitter

Chelsea Clinton announced on Twitter that she is pregnant with her second child, due sometime next summer.

The daughter to Democratic presidential front runner Hillary Clinton already has one child, one-year old Charlotte Clinton Mezvinsky.

"Feeling very blessed and grateful this holiday season," Chelsea Clinton, age 35, posted on Twitter.

Shortly thereafter, Hillary Clinton responded with her own tweet.

Clinton often mentions her granddaughter in campaign speeches about the need to address the nation's challenges for future generations, and the birth of her second grand child would coincide with the two party's nominating conventions.

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Photos: Chelsea Clinton through the years