Yes, they occur once in a blue moon on their own.
Basically they are supposed to be a freak occurrence, like dwarfism or gigantism, or a pregnancy defect/complication like having conjoined (siamese) twins.
Not something you experience more often than not.
But what are your chances when you're doing IVF and/or you take fertility drugs to help the body along?
Countless orders of magnitude higher than normal. You go from your chances being "like winning the lottery" to "like hitting two red lights in a row sometime during your trip".
Anyhow, thanks for the clarification, but my point still stands.
The article (above) suggests that when you choose to have children, the photo above of 5 babies (quintuplets?) is what you're inviting into your life. That is clearly being hinted at or suggested.
You know how so many people aren't content to stick to the facts, but find the need to exaggerate? Like the people who say, "I don't want to be stuck at home with 15 kids, so I have to use birth control." They always pick an exaggerated or worst-case. I think CNN is doing the same thing.