Limited by her fertility and health, a woman can only physically give birth so many times during her lifetime. A few women, like Michelle Duggar and "Octomom" Nadya Suleman, have become famous for their supersized broods, but who has the distinction of giving birth to the most children ever?

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.

The Monastery of Nikolsk recorded information about births for the Moscow government, and the monastery reported in 1782 that Feodor was a 75-year-old peasant who had 87 children total between his first and second wives, 82 of which were alive that year.

A 1783 issue of The Gentleman's Magazine in London included a letter about the Vassilyevs, postulating that Feodor’s large number of offspring was probably due to his fecundity rather than that of his wives. The writer of the letter asserts that the number of kids Feodor sired, “however astonishing, may be depended upon” because an English merchant traveling in St. Petersburg directly spoke about the Vassilyevs and claimed that Feodor was going to meet the Empress of Russia. Later, the French Academy attempted to ascertain whether the Vassilyev case was authentic, and were supposedly told by a member of the Imperial Academy of St. Petersburg that no verification was needed, as the sons and daughters of the Vassilyevs lived in Moscow and received government favors for their large brood.

Despite the monastery’s record and the letter in The Gentleman's Magazine, modern doctors and skeptics doubt that it would be physically possible for a woman to give birth, via 27 pregnancies, to so many babies. Other publications and articles in the late 1700s and 1800s mention the Vassilyev case but warn readers to take it with a grain of salt.

Because women who give birth to triplets and quadruplets usually deliver them prematurely, it’s possible that Mrs. Vassilyev could have fit in 27 pregnancies during her childbearing years. Moreover, it’s conceivable (pun intended!) that she gave birth to multiple sets of multiples, because some women can have a genetic predisposition to hyperovulate (release multiple eggs in one cycle), which greatly increases the chances of twins and multiples. Depending on when she started menstruating and when she began menopause, Mrs. Vassilyev may very well have been pregnant 27 times, but the likelihood of her (and nearly all of her babies) surviving childbirth and infancy, respectively, is low, especially for poor Russian peasants in the 1700s.

The number of births and the number of healthy infants who survived were probably exaggerated over time, but Mrs. Vassilyev currently holds the official, validated world record for being the most prolific mother ever. And we doubt that will be broken any time soon.