If you're requiring all births to be single child only, I'm unaware of that being tracked anywhere. This woman had 20 single baby pregnancies which could be the highest single baby births from one woman... However if you mean # of pregnancies... I see a woman with 27 pregnancies leading to birth here:
Source
And what's crazier is that of those 27 pregnancies, she had a total of 69 children because she gave birth to 16 pairs of twins, seven sets of triplets and four sets of quadruplets. The children were born between 1725-1765.
I remember reading somewhere there was another with 31 pregnancies, but I don't see it documented anywhere... the 27 is official.
