Any variables that can be used to get the total number of children in the household in NHIS data?

I am studing childless couples and want to use NHIS data 1980-2014. Is there a consistent variable in NHIS that allows one to deremine the total number of children in the housheold (total includes own, adopted, and step children) for each year 1980-2014. So far, I browsed IHIS datasets, but could not detrmined such variable (there are some relevant variables but they are observed only in a specific year). I also tried downloading NHIS questionnares for a number of different years (english version), but had trouble with pages noit loading. Any guidance is highly appreciated!

In the IHIS data, you can use the RELATE variable to determine the number of children in a household. Specifically, RELATE=41 identifies a biological, adopted, in-law, step, or foster child of the householder. RELATE=43 identifies a child of the householder’s unmarried partner. RELATE=44 identifies a child of an ineligible householder (use with caution). You can create a total count of the number of children in a household using a statistical package such as SAS, STATA, or SPSS.

Hope this helps.