The Extraordinarily (and Impossibly?) Fertile Mrs. Feodor Vassilyev

Many of us recall looking through the Guinness Book of World Records and seeing the entry for the mother with the most children. When I had the paperback version (yes, it’s a real book, and once upon a time many people owned it), it referred to a Russian woman who allegedly had 69 children. She had twins, triplets, and quadruplets in order to add up that many babies. Oh yes, there’s more to the story than was printed at the time.

Mrs. Feodor Vassilyev, a Russian peasant who lived in the 1700s, holds the official Guinness World Record for the highest number of children birthed. She and her husband, Feodor, lived in Shuya, Russia. We don’t know her first name (although some sources say her name was Valentina), but we do know that she's claimed to have given birth to 16 sets of twins, seven sets of triplets, and four sets of quadruplets in her childbearing years (1725 to 1765). Only two children didn’t survive past infancy, leaving her with 67 healthy children.
What makes the Vassilyev story even weirder is that Feodor apparently had another 18 children (six sets of twins and two sets of triplets) with his second wife. Although it sounds implausible, a few primary sources and contemporaneous accounts about the Vassilyevs exist.

You are forgiven for being skeptical, but first read about the documents that led us to what we know about Mrs. Vassilyev and her family that put Mother Hubbard to shame, at mental_floss.   
Bonus: I also found out that the founder of the Guinness Brewery that later gave rise to the records book, Arthur Guinness, and his wife Olivia had 21 children.