Sex education for intermediate schoolchildren in Wairarapa sticks to biology and sidesteps questions about sexuality.
Parents elsewhere have raised concerns about children as young as 12 being given graphic information about sex in school lessons.
Lakeview School principal Ed Hodgkinson said the lessons involving Year 7 and 8 students were focused on changes in puberty. Guardians were informed of the class and could remove their children if they wished.
Mr Hodgkinson, who also heads the Masterton principals cluster for 14 district schools, said questions about sexuality remained unanswered and health nurses helped deliver the lessons, which were drawn from a long-standing health syllabus.
"There is a curriculum and it stays within a biological outline, menstruation, for example, and how their bodies are changing.