Michelle Obama says she felt "lost and alone" after suffering a miscarriage 20 years ago.
Michelle Obama has opened up in her memoir about having a miscarriage 20 years ago and using a fertility treatment to conceive her two daughters.
"We were trying to get pregnant and it wasn't going well," Mrs Obama, 54, writes in her upcoming memoir.
"We had one pregnancy test come back positive, which caused us both to forget every worry and swoon with joy, but a couple of weeks later I had a miscarriage, which left me physically uncomfortable and cratered any optimism we felt."
In the memoir, called Becoming, she writes of being alone to administer herself shots to help hasten the process.
Her "sweet, attentive husband" was at the state legislature, "leaving me largely on my own to manipulate my reproductive system into peak efficiency".
The revelations are some of many included in the book from a former first lady who has offered few extensive comments on her White House years.
"I felt like I failed because I didn't know how common miscarriages were because we don't talk about them," the former first lady said in an interview broadcast on ABC's Good Morning America.
"We sit in our own pain, thinking that somehow we're broken."
She said she and Obama underwent fertilisation treatments to conceive daughters Sasha and Malia, now aged 17 and 20.
Mrs Obama also writes openly about everything from growing up in Chicago to confronting racism in public life and becoming the country's first black first lady.
She also lets loose a blast of anger at President Donald Trump.
She writes in the memoir that Trump's questioning of whether her husband was an American citizen was "crazy and mean-spirited ... its underlying bigotry and xenophobia hardly concealed. But it was also dangerous, deliberately meant to stir up the wingnuts and kooks.
"What if someone with an unstable mind loaded a gun and drove to Washington? What if that person went looking for our girls?" she writes.
"Donald Trump, with his loud and reckless innuendos, was putting my family's safety at risk. And for this, I'd never forgive him."
Trump suggested Obama was not born in the US but on foreign soil - his father was Kenyan. The former president was born in Hawaii.
Mrs Obama also expresses disbelief over how so many women would choose a "misogynist" over Clinton in 2016. She remembers how her body "buzzed with fury" after seeing the infamous Access Hollywood tape, in which Trump brags about sexually assaulting women.