What was the combined birth weight of the heaviest set of twins in kilograms?

The combined birth weight of the heaviest set of twins, which you selected as 12.6 kilograms, is supported by documented records. This weight reflects the extraordinary circumstances surrounding the birth of these twins, who were likely significantly larger than the average twins, which typically weigh less.

In the realm of record-breaking births, it is not uncommon for the heaviest twins to greatly surpass standard birth weights, particularly in rare cases influenced by various factors such as genetic predisposition or maternal health. The 12.6 kilograms for this set of twins stands out and is well-documented, making it the correct choice. This information highlights the significance of understanding both average statistics and extraordinary cases when discussing phenomena like birth weights.