Reveal this until now, but I wish she had. I think it would help so many people who experience difficulties getting pregnant to hear from someone like her:
"She describes wanting to protect her daughters from the glare of public life, and recounts her difficulties becoming pregnant and suffering a miscarriage. She reveals, for the first time, that Malia and Sasha were conceived through in vitro fertilization, and describes feeling resentful about administering shots to herself while her husband was away at his job in the state legislature: “None of this was his fault, but it wasn’t equal, either,” she writes."
https://www.nytimes.com/2018/11/09/books/michelle-obama-book-becoming.html?smid=fb-nytimes&smtyp=cur&fbclid=IwAR07KHkzmwdIukjIFpjPt9Vcp2pGselvf0jYhqBWiYFB1VYLqmg4ZqzDFec