The largest number of children ever born to one woman was 69 :

The greatest officially recorded number of children born to one mother is 69, to the wife of Feodor Vassilyev (b. 1707–c.1782), a peasant from Shuya, Russia. In 27 confinements she gave birth to 16 pairs of twins, seven sets of triplets and four sets of quadruplets.
        Numerous contemporaneous sources exist, which suggest that this seemingly improbably and statistically unlikely story is true. The case was reported to Moscow by the Monastery of Nikolsk on 27 Feb 1782, which had recorded every birth. It is noted that, by this time, only two of the children who were born in the period c. 1725–65 failed to survive their infancy.