Serena Williams shared details from her life-threatening pregnancy. USATSI

Bringing new life into the world is always a joy, but it can have seriously scary ramifications. Tennis legend Serena Williams learned that firsthand in September, when she nearly lost her own life giving birth to her first daughter, Olympia Ohanian.

Williams has already talked about the myriad medical problems she dealt with after the delivery, including blood clots and a burst C-section. On Wednesday, however, Williams addressed the systemic issues that allowed her to get through that situation when so many don't.

In an opinion piece for CNN, Williams did not mince words.

"I almost died after giving birth to my daughter, Olympia," she began. Williams then described the process through which her daughter was delivered.

"While I had a pretty easy pregnancy, my daughter was born by emergency C-section after her heart rate dropped dramatically during contractions," she said. Williams then said that the next six days were a hellish experience in which she didn't know if she'd live or die.

"It began with a pulmonary embolism, which is a condition in which one or more arteries in the lungs becomes blocked by a blood clot," she said. "Because of my medical history with this problem, I live in fear of this situation. So, when I fell short of breath, I didn't wait a second to alert the nurses.

"This sparked a slew of health complications that I am lucky to have survived. First my C-section wound popped open due to the intense coughing I endured as a result of the embolism. I returned to surgery, where the doctors found a large hematoma, a swelling of clotted blood, in my abdomen. And then I returned to the operating room for a procedure that prevents clots from traveling to my lungs. When I finally made it home to my family, I had to spend the first six weeks of motherhood in bed."

Next, Williams talked about her medical team, and the fortune she had to have had them on hand.

"If it weren't for [my doctors'] professional care, I wouldn't be here today," she wrote.

Williams then went on to talk about the alarming mortality rate of black women that give birth, saying that according to the CDC they're three times more likely to die due to complications in pregnancy or child birth. She also wrote that according to UNICEF, there are 2.6 million newborns that die, with 80 percent dying from preventable causes.

Williams said that efforts must be made to save mothers and babies in underdeveloped countries. Without her status, or her team, there was a chance that she herself wouldn't make it. And Williams herself testified to the unfairness of that: "Every mother, everywhere, regardless of race or background deserves to have a healthy pregnancy and birth," she said.

Williams sat out of January's Australian Open to continue her recovery process, but she seems primed to return to the French Open. There, she will go for her 24th Grand Slam -- which would tie her for the most all time with Margaret Court.