Serena Williams won't attempt to defend her Australian Open crown. USATSI

Serena Williams won't be defending her Australian Open title after announcing that she won't play in 2018's first Grand Slam following the birth of her daughter, Alexis Olympia. That she was even considering playing in a slam just five months after giving birth is incredible -- especially after she revealed to Vogue that she suffered major health complications after the delivery. 

Williams said she had to undergo an emergency cesarean section after her daughter's plummeting heart rate reached dangerously low levels during contractions. Her daughter arrived just fine, but Williams endured a six-day ordeal with a pulmonary embolism that led to multiple surgeries.

"That was an amazing feeling," Williams said of having her crying daughter fall silent on her chest seconds after being born. "And then everything went bad."

Per the Vogue story:

The next day, while recovering in the hospital, Serena suddenly felt short of breath. Because of her history of blood clots, and because she was off her daily anticoagulant regimen due to the recent surgery, she immediately assumed she was having another pulmonary embolism. (Serena lives in fear of blood clots.) She walked out of the hospital room so her mother wouldn't worry and told the nearest nurse, between gasps, that she needed a CT scan with contrast and IV heparin (a blood thinner) right away. The nurse thought her pain medicine might be making her confused. But Serena insisted, and soon enough a doctor was performing an ultrasound of her legs. "I was like, a Doppler? I told you, I need a CT scan and a heparin drip," she remembers telling the team. The ultrasound revealed nothing, so they sent her for the CT, and sure enough, several small blood clots had settled in her lungs. Minutes later she was on the drip. "I was like, listen to Dr. Williams!"

But this was just the first chapter of a six-day drama. Her fresh C-section wound popped open from the intense coughing spells caused by the pulmonary embolism, and when she returned to surgery, they found that a large hematoma had flooded her abdomen, the result of a medical catch-22 in which the potentially lifesaving blood thinner caused hemorrhaging at the site of her C-section. She returned yet again to the OR to have a filter inserted into a major vein, in order to prevent more clots from dislodging and traveling into her lungs. Serena came home a week later only to find that the night nurse had fallen through, and she spent the first six weeks of motherhood unable to get out of bed. 

While Williams has put her health scare behind her, she also told Vogue that she's not ready to give up on her tennis career at 36 and be a full-time mom. She and her husband, Alexis Ohanian, the co-founder of reddit, just found a new home in Silicon Valley, but Williams is still eyeing more Grand Slams.  

"To be honest, there's something really attractive about the idea of moving to San Francisco and just being a mom," said the 23-time Grand Slam winner. "But not yet. Maybe this goes without saying, but it needs to be said in a powerful way: I absolutely want more Grand Slams. I'm well aware of the record books, unfortunately. It's not a secret that I have my sights on 25."  

That number of Grand Slam wins would surpass the record 24 won by Australian legend Margaret Court, who is possibly more well-known now for her outspoken criticisms of gay and transgender players

"And actually, I think having a baby might help," Williams said. "When I'm too anxious I lose matches, and I feel like a lot of that anxiety disappeared when Olympia was born. Knowing I've got this beautiful baby to go home to makes me feel like I don't have to play another match. I don't need the money or the titles or the prestige. I want them, but I don't need them. That's a different feeling for me."