Health officials in Fiji say children reach puberty at a younger age and fall pregnant because they do not know about the consequences of their sexual behavior.
Data published by the Ministry of Health shows an increase in pregnancies among 10 to 14 year old girls, from eight in 2000 to 36 cases by 2004, with the problem being prevalent among indigenous Fijians.
The coordinator of the Fiji adolescent and reproductive health programme, Sister Sulueti Duvaga, says the the data is very concerning.
"We believe, because young girls are reaching puberty at a younger age now, as we have seen before. Young girls and boys were getting mature at 15 or 16. Now they are getting mature at a younger age, at nine or ten. When they reach puberty, most of them are not informed about the changes that they go through."
But Sister Duvaga also says more research is needed to find out about other factors that may cause the problem, such as abuse, incest and peer pressure.
She says the ministry is preparing a questionnaire to be distributed among teenagers.