Beyonce suffered a heartbreaking miscarriage before falling pregnant with her daughter, according to her husband Jay-Z.
The rapper made the revelation in a new song Glory which he posted on his social website Life and Times today.
The tune is a tribute to the couple's new baby, Blue Ivy Carter, who was born in New York late Saturday night.
In the song, Jay-Z, 42, talks about where the child was conceived (in Paris) and even reveals that Beyonce, 30, had a lost a child one point.
'Last time the miscarriage was so tragic/We was afraid you'd disappear/But nah baby you magic.'
The sound of crying Blue Ivy can be heard at the end of the song.
The track was produced by Pharrell and credits the new arrival as 'B.I.C.'
Other moving lyrics include: 'The most amazing feeling I feel, words can't describe what I'm feeling for real / Baby, I paint the sky blue, my greatest creation was you.
'You're the child of destiny / you're the child of my destiny / you're my child with the child from Destiny's Child.'
Early reports claimed the singer gave birth via C-section, but the couple now say otherwise.
The released a joint statement today, saying Blue 'was delivered naturally at a healthy 7 lbs and it was the best experience of both of our lives.'
The couple adds, "Her birth was emotional and extremely peaceful, we are in heaven. We are thankful to everyone for all your prayers, well wishes, love and support.'
It's the first child for the power couple, who wed in 2008 in a private ceremony after a years-long courtship.
Beyonce announced her pregnancy to the world last August at the MTV Video Music Awards with a simple rub of her swollen belly.
Celebs close to the couple have tweeted congrats. Beyonce's sister, Solange Knowles, tweeted Sunday morning: 'The most beautiful girl in the world,' while Beyonce's close friend Gwyneth Paltrow also tweeted: 'Welcome to the world Blue! We love you already.'
Meanwhile, it has emerged that the A-list couple have infuriated other new parents by enforcing a lockdown at the hospital where they had their first child together.
The pop superstars reportedly spent a staggering $1.3 million for pricey renovations to an exclusive recovery area at one of Manhattan's swankiest hospitals - including a bulletproof door to her room.
hey also have their own private security force working an area alongside hospital security already at Lenox Hill Hospital.
But other parents have bitterly complained that the intense measures have not just given privacy to the superstars and their baby - but made other new parents miss out on precious moments with their own newborns.
Fuming parents said they were essentially put on 'lockdown' so that the pampered songstress and her party could come and go as they pleased.
'They just used the hospital like it was their own and nobody else mattered,' blasted new dad Neil Coulon, who said his efforts to see his premature, newborn twins in the neonatal ICU were disrupted at least four times by the arrival of Beyonce and her crew.
Coulon - who is from Jay-Z's native Bedford-Stuyvesant in Brooklyn - said some of his relatives drove 4 1/2 hours to see his girls, only to be shunted aside for Beyonce.
'They locked us into the NICU and would say, "You can't come out to the hallway for the next 20 minutes." When I finally was able to go back out, I went to the waiting room and they'd ushered my family downstairs!