Williams is on the cover of Vogue's February issue.
She told the publication that the problems began after Alexis Olympia's heart rate started to drop during her delivery and it was decided that the best option would be to have Serena undergo an emergency c-section.
"That was an wonderful feeling", Williams said.
"And then everything went bad".
An ultrasound, which the doctors insisted on performing first, found nothing, but later, it was revealed she had "several small blood clots" in her lungs.
'I was like, a Doppler? I don't need the money or the titles or the prestige. "I was like, listen to Dr. Williams!" she quipped.
The ordeal continued for another six days.
But the drama didn't end there and Serena's C-section wound opened, leading to more surgery, whereby surgeons found a large haematoma had flooded her abdomen.More news: I won't forget what you said - Conte tells Mourinho
She was then sent for further surgery, to have a filter inserted into a major vein to stop more blood clots dislodging and travelling to her lungs, and she wasn't allowed home from the hospital until a week later. She also didn't have a night nurse to take care of her daughter. "I want to teach her that there are no limits".
"I was happy to change diapers, but on top of everything she was going through, the feeling of not being able to help made it even worse", he said.
"Consider for a moment that your body is one of the greatest things on this planet, and you're trapped in it".
Serena is on the mend now physically, but she is still dealing with plenty of emotional ups and downs when it comes to parenting. The 36-year-old tennis superstar told Vogue about the incredible moment when the baby stopped crying as soon as she was placed upon the new mother's chest.
Williams needs just two more Grand Slam championships to break Margaret Court's all-time record of 24, and she told Vogue she still has every intention of doing so.
"Sometimes I get really down and feel like, Man, I can't do this", she says.
The reigning champ and seven-time victor had hoped to defend her Australian Open title but pulled out following the complications.
Katherine Lam is a breaking and trending news digital producer for Fox News.