Ten per cent of the women who gave birth in the Gisborne region last year were teenagers.
Figures released to the Herald by Statistics New Zealand showed the number of teen births as a proportion of total births in Gisborne was the highest in the country at 10.1 per cent, followed by the Hawke's Bay region on 7 per cent and Northland on 6.5 per cent.
In Auckland, 3.4 per cent of the women who gave birth last year were teenagers.
The proportion of teenage births was lowest in the Otago region on 2.2 per cent.
The data comes on the back of the announcement the teenage birth rate in New Zealand has halved since 2008.
Statistics New Zealand data released today showed the teen birth rate had dropped each year since 2008 when it was 33 births per 1000 women aged 15 to 19. Last year the rate dropped to 16 births per 1000 women in that age group.
Just 4.2 per cent of the 59,430 births in 2016 were to teen mums, compared with 8.1 per cent of births in 2008.
The Statistics New Zealand data showed 15 women under the age of 15 gave birth last year while 2466 New Zealand women between the age of 15 and 19 gave birth - both were the lowest figures since 2000.
Family First NZ national director Bob McCoskrie said he believed the drop was because the message to abstain from or postpone sexual involvement was getting through.
"There is also evidence that the drop is because more and more teenagers are delaying sex. According to the Youth 2012 survey undertaken by Auckland University, the proportion of students who reported ever having had sex was similar in 2001 and 2007 (approximately a third) but was lower in 2012 - down to 24 per cent. And less than 19 per cent said they were currently sexually active," he said.
"Groups like Family Planning will argue that it is because of contraception and the morning-after pill that the teen pregnancy rate has dropped but the evidence refutes that claim. The Youth Survey showed that contraception use had not improved over the last 10 years, and in fact sexually active teens are being riskier with a 7 per cent decrease in the use of condoms between 2007 and 2012.
"And a US study found increased access to emergency contraception increases the rates of sexually transmitted diseases, risk taking and a false sense of security, while doing nothing to reduce the number of abortions. A study in the Journal of Health Economics in January 2011, conducted in the United Kingdom, found that widespread access to emergency contraception did nothing to reduce pregnancy but increased STD rates by 12 per cent."
Family Planning chief executive Jackie Edmond said young people delaying their first sexual encounter may have been a factor but said the small drop in the number of students who reported having sex in the Youth 2012 survey did not explain the huge decrease in the rate of teen pregnancies.
"It's probably a mixture of things. There's no definitive evidence of what it is," she said when asked why the number of teen pregnancies had dropped.
She said increased access to more reliable contraception like IUDs and other implants was likely to be part of the reason, as was better education.
Edmond said she had not seen any correlation between social media or television use and teen pregnancy or birth rates.
"There are mixed views on programmes such as 16 and Pregnant. Some people say it glamourises the situation while others say it's the reality for young parents."